A lot of it is a weak sense of self, a lack of identity. I'm a ((insert style)-biker, and do it right, all those other folks are just doing it wrong. So I have to put them down to build myself up, because if I don't do it like them, my sense of self gets degraded. And for people who do it like everyone else, they look at folks like me who don't, and say, what's wrong with you? It's all about threats to your identity.
Maybe not the most cogent thought I've ever had, but I'll re-visit it.