Nothing against psionics by itself. The flavor of inherent mind powers is ok, and the system it used in 3.x and 4e was fun and balanced.
But it's jarring for me when it exists together with magic and aven more jarring is described as something significantly different.
If a setting had psionics as the only supernatural powers, I'd be fine with it. But if it has psions and wizards and clerics - no, thank you. Too much of a kitchen sink for me.