A hipster is basically someone who thinks because you like mainstream things they are superior to you and they are 9/10 the ones who complains constantly about music in the current time but are the same ones that praise the music that they used to insult back in the days. They will typically insult anyone who likes mainstream music because they.....think they are not independent thinkers.
Non-hipster: Oh I like this song
Hipster: I don't
Non-hipster: Okay, what do you think is wrong
Hipster: It's brainwashing you and I don't want to be a corporate lap-dog, it's making you a follower so no one should like it.
Non-hipster: Get those negative and stereotypical superiority feelings away from me.