I think most people that refer to themselves as hipsters do so with at least a little irony, but I've met one or two who will tell me that they're hipsters with entirely straight faces. I agree with Anyways that, while it's certainly a caricature, it's a caricature that at least some people take on as an identity. Its an easy cop out to view people as categories instead of individuals, and we all do it, but many of us do it to ourselves as well as others. People assume identities because they're safe. It takes a lot of thought to decide who you are, and its scary for many people to think "I am the only one." Identifying with a group, any group, allows you to have a sense of self without as much work, and also gains you a sense of community. Whether we're talking about fashion, music, religion, politics, or what have you, taking on an identity answers a lot of questions for you. So we can say "I don't believe in labels" all we want, but it probably isn't true, and in the end, when people are applying the labels themselves, they can hard to avoid.