"Nerds" and "hipsters" are both rather distinct groups of individuals, and within each of these groups the individuals share a number of traits in common. Given that the traits are quite specific and isolated, it's not at all a case of generalization.

As a professional, I work with whomever I have to in order to complete the tasks at hand. But given how many of my fellow colleagues with all sorts of jobs and all sorts of background have similar problems with "hipsters", I'm quite sure the problem is not with me, and it is not with my colleagues, either.

Obnoxiousness and ego just happen to be two of the traits inherently associated with "hipsters". I can't help that, my colleagues can't help that, and even the "hipsters" themselves can't help that. It's just who they are; it's a big part of what makes them "hipsters".