Personally, I like psionics, but I'm virtually the only one in my group.
Speaking only for the guys in my group, most of them dislike psionics because of the flavor, not the mechanics.
While I want to ask what their big issue with the flavor is, I've found most people who hate it tend to take the approch of hating psionics first, finding reasons in the fluff to hate it second, if simply because the flavor of psionics can be turned to support just about any style of character you want.