As an aside, the first time I undertook to provide an in-depth counseling session as a young man, I tried to guide my best friend through struggles of the heart using only the knowledge of psychology gleaned from the back of the Complete Psionics Handbook. And, while he didn't listen, everything I said was completely accurate.
I think that I could hold up 2e's Psionics as an argument in favor of the streamlined, some might say homogenized approach of 4th edition. Back in the day, psionics gave players a tremendous amount of versatility and flexibility, but the cost was that a lot of the powers were incredibly unhelpful. This is not to say that it was impossible to find a use for seeing sound or feeling light, but the process of activating and maintaining most powers was Byzantine enough that you really had to work at it. Meanwhile, the fighter's kicking in the door and stabbing orcs, and the wizard is dropping lightning on dudes...but by dammit, if the evil Duke puts some poison in a goblet, you're sure as hell going to be the one to notice! After drinking it! Good luck!
It was tough, as a young man, not to gravitate solely towards the promise of the few Major powers that had some damage-dealing capacity. It was equally difficult not to fall to the temptation of just creating Dimension Doors and shoving dudes halfway through them, which was---if memory serves---the second-most damaging power in the book after Disintegrate. The mental powers were cool in theory, but prior to the simplified Dark Sun rules for mental combat, using them was...inelegant. Inelegant like pausing a tennis match and forcing both players to wrestle a greasy sow. Or that simile. The Metapsionic powers were so heartily dependent on a campaign full of psionics that I never once saw a player touch them. Again, though, we were in high school; I'm sure homebrew campaigns existed where psionicists engaged in pulse-pounding mental combat while chatting amiably with friends at a gala ball.
My campaigns, people mostly took Psychometabolic/Psychokinetic powers, made their hand a sword, and hoped they rolled something awesome on the Animal Affinity table.
Nonetheless, I loved psionics. I loved the Discipline presentation. Sure, mages and clerics had their spells compartmentalized into schools/domains (Were they called domains in 2e? Looking this up would be cheating, but I feel ancient for not knowing off the top of my head), but even a specialist wizard was basically just saying "I can sacrifice Charm Person for easier access to Fireball." The Disciplines seemed so exotic, so distinct, and so wholly defining that it felt much more heavily like a choice.
I loved Psionics in 3e too; both times, actually. The first iteration gave me my beloved Disciplines, an awesome new way to play in the Psychic Warrior (A psionicist who does die immediately when glared at!), and all of the slightly clumsy, fumbling complexity I'd come to expect. Still, I'm not going to claim for even a moment that I didn't prefer the reworking of the system for 3.5. Frankly, even though I bemoaned the creation of 3.5 alongside much of the internet, I vastly preferred everything about it.
I though that the new Augment approach was a powerful way to distinguish psionics from magic (Though I can tell I've fully settled in 4e, because that sentence was originally "psionic magic from magic."). I liked that it allowed characters to approach having "always on" powers at the expense of versatility. It's entirely likely that people were doing this for years prior through a combination of metamagic feats, but I've never liked metamagic feats; out of the several-score 3e and 3.5 characters I've made, I don't think I ever took one other than Natural Spell. Even without enjoying the metamagic approach, though, I appreciated how psionics provided a counterpart to its approach; instead of applying the same rote alteration to all of my incantations, I might tweak this power one way for a certain encounter, while fiddling with it in a different fashion later. Obviously, I didn't much care for metapsionic feats, which seemed unnecessary to me; I imagine they were necessary to someone who builds their characters with an eye towards mathematical optimization though, and so they existed.
This era's psionics did an even better job of distinguishing Disciplines, and making a character whose interest was telepathy feel wholly different from one who wanted to agitate molecules with his mind. I still fancied the psychometabolic powers, but I also fell fast and hard for the improved approach to metacreativity.
I love summons. I love options. I love refluffing powers.
Being able to combine those three was a dream. For me, the fun of running a summoner is in treating her minions as additional characters. Constructing their appearances, their powers, and their history was almost as fun as writing the summoner herself. I built one memorable character (whose update to 4e for the game I mentioned last entry is part of what spurred this topic) around a variety of Astral Constructs with names like "Screaming Aisha" and "The Orphan Forge." Each Construct was an elaborately described denizen of the Abyss, and I detailed their histories and ecologies before devoting at least a paragraph to how the character summoned each one. Obviously, that sort of reflavoring could just as easily be applied to summoned monsters, or even Nature's Ally creatures; but being able to build the monster to my specifications was something only psionics could bring me.
I wrote another beloved character using the psionics rules, including what I still consider to be the most broken element therein. Since psionic races manifested their innate "psi-like" powers by spending power points equal to their level (for free!), Duergar expansion quickly got ridiculous. I built a psychometabolizing ninja duergar who spent the entire game invisibly, Huge, and heavily beclawed. In the era of the one-encounter workday, being able to enhugify oneself for two hours was just about as good as permanent.
There's a reason, other than the alphabet, why I'm waxing rhapsodic about the psionics of yore: try as I might, I've yet to fall in love with those of 4e.
I already spoke about how dreamy the Battlemind is, and in particular how much I like Body Double. That's all true, but Body Double could be a Daily stance and I'd still be pumped about the whole thing. I also think Monks are neat, because I've always loved monks; but they're a psionic class in name (and feat selection) only. The "true" psionic classes, the ones with the wonky augmentation powers, don't get me as pumped as I would like.
I've rolled some, certainly, but most don't make it past the planning stages. I'm playing one now and about to submit two more to other games, but I'm largely doing the latter because I'm stubborn. I know I'm not playing psionic characters, I feel like I should, so I'm making some. I could as easily have presented either character as wholly different classes or combinations thereof. I'm excited about both characters...but I'm still not excited about psionics.
And, to return to the tip-topic of this post, I think the reason is partially Disciplines. It's partially the new Augment approach, though.
I loved Augmentation back when it was taking a power that stood on its own, and sacrificing future resources to make that power better at standing on its own by improving whatever it was already doing. Certainly, some augmentation options had other effects; my aforementioned Duergar got excellent use out of using his racial expansion reactively, for instance. But in general the idea behind each augment was direct. If the power didn't gain a linear or multiplicative bonus, such as doing more dice of damage or increasing its duration by a tremendous factor, then it usually gained some benefit to its core application---ie, an attack power targeting more creatures.
In 4e, I can use my at-will power to perform fairly standard feats, some of which can get impressive at higher levels; I can also spend some of my precious power points to get an encounter-power's worth of use out of the same attack. I'll do more damage, affect more targets, or have some other greater effect.
However, 4e augmented powers go through this awkward pubescent stage that feels like leveling a Magicarp. I can spend roughly half the resources I otherwise would, but gain an effect that is "better" albeit more hyperspecialized. So, so hyperspecialized.
Some of these middle powers actually remind me of 2e's Metapsionics. There's an obsession with the Will defense that doesn't serve much purpose if you're fighting goblin archers, or earth elementals, or (non-cranium) rats, or kruthiks. Some of the corner cases are handy, like the at-will I just picked up for my lvl 1 Ardent that can heal a dying ally. Since the power normally grants thp, being able to bring a friend back to his feet is great.
Except that for two power points instead of one, I could grant that same friend a healing surge. And if I choose to bring the friend back from the dead before I've popped that two-point use, and I'm level 1 (as I am) I no longer have that option for the rest of the fight. I can certainly see an argument being made that having 2 shots (for 2 power points) at bringing a dying ally back is better than one. But I also just spent two paragraphs scrabbling to find a justification for an attack. I don't have to spend two paragraphs justifying Spinning Strike.
Trying to pick powers for a 4e psionic character is an exercise in exhaustion, blended with guilt. It's exhausting to try and juggle the value of three different applications of each of five or six potential at-will powers, then determine which of your extant at-wills (after level 3) you're going to drop. It's a process rife with guilt, at least for me, because I find myself just skipping the middle powers. I absolutely appreciate the attention my beloved psionics got in 4th edition. I think it's awesome that they were given so many powers, with such depth. But I can't shake the feeling that the powers themselves would have been much more exciting---body double exciting---if designers hadn't had to worry about that weird middle state while designing them. And while I'm hoping to discover that the middle-tier options are super awesome, and I love writing things that I will later prove wrong, I feel like I'd be just as satisfied with my characters if they completely skipped those middle riders.
Or, at least, my Ardent. I recognize that psions get off a lot better than the melee classes, since so many of their powers pick up an extra target or throw out some more damage. It may be that I just don't like how Ardents work, which is part of why I'm rolling with one.
Either way, though, the other thing I miss from 4e psionics is the ability to specialize in a Discipline. I'm fine flavoring my powers along certain lines, and normally I love the wide open power selection of 4e. But I definitely wouldn't mind seeing psions, or even battleminds, get the Essentials Mage treatment. A metabolic battlemind picking up temporary hitpoints and forming weapons like the Warhammer: Age of Reckoning Marauder would be sweet. A psion who flickers and teleports all around the map, leaving deadly whorls of distorted space in his path, would also be awesome.
I recognize that the design intent seems to be a splitting of extant Disciplines into receptacles roughly shaped like the original 3.5 psionic classes, and as far as that goes I think Wizards was successful. But the end result is that the power source, as a whole, lacks that extra layer of depth that I've previously enjoyed.