They are to some extent but my point is that a doctor from NYC or Austin TX is more likely to think like someone from SV than a programmer from Boise or Bangor.
The SV way of thinking is present to some extent in most urban people of similiar socioeconomic class. A plumber from SF will not necessarily take the same things for granted that a programmer from SF will.
I think class is definitely a part of it, but I believe SV's paradigm is notably distinct from other geographies. A programmer from Chicago is much less likely to talk about disruption as an unalloyed good, or to take a militant free-speech line that refuses to consider race or class.