I've always mentally translated hipsterism as "off the rack depth" i.e. lacking real character. Totally different from people who are genuinely idiosyncratically interesting.
I think there are two breeds of hipster. One is genuine in is appearance and interest. The other is just trying to be trendy. It's hard to tell the difference until you actually interact with them on a regular basis.
... HDs are the poseurs who adorn themselves in hipster trappings but shove their nouveau "status" and newly acquired tastes in other peoples' faces and insist on being snotty, obnoxious assholes. Some hipsters can be hipsters and not be pricks about it, getting along and mingling with people outside their clique and crowd. HDs cluster in self-segregated groups that are reluctant to have anything to do with "other people." I've seen it happen, and in all sorts of environments. The HD has a wider territorial range than the American gray squirrel.
... more like middle-class poseurs.
Yeah, you guys pretty much nailed what I was perceiving and trying to explain but failing to: the sheer inauthenticity of it.


Seriously, though, I live in a university city so have a plague of hipsters as well. They annoy me just as much as those idiots walking around with their trousers around their knees. Perhaps I've not come across a "genuine" hipster, because the ones I've come across are shallow and completely self-centred.
I'll have to remember that the next time I'm walking in the area to wear a helmet, just in case.