I've noticed that, too. Whether it's psionics, specific classes, or whatever, people who aren't fond of a particular mechanic sometimes seem to think that they're making a magnanimous concession by saying, "Okay, it can be in the game, but only in an uninteresting, half-functional form."
This is supposed to be the "everything but the kitchen sink" edition, so if the fanbase really wants something, WotC should make sure they do that thing well if they decide to include it at all. If people don't want to include those things in their particular game that they're running, they can just say, "Make your characters now, but remember, no psions/barbarians/warlords/etc."