Also, I've never met anyone who actually does what your definition of a "real hipster" does. Most of the hipster people I know have that nihilistic attitude which manifests in completely insincere cultural references, but I don't think they're doing it to be cool and detached. I DO think some might look down on a sort of artistic sincerity, though. I might be guilty of this--I was kind of shocked at how honest and earnest non-postmodern literature was after not reading it for a while. Also, this.
And I've never met anyone who ACTUALLY dislikes bands because they're mainstream and likes bands because they're not. I really think that's a pretty cynical way of looking at it. Slowed down, chopped and screwed 80s pop songs just have that "trapped in cultural decay" vibe they're looking for. If it were mainstream, I think they'd like it. I mean, they like Animal Collective, and that's pretty popular. I think.
@gmanyo get in this thread.