I have stayed in SF for almost a decade and have no plans to leave.

Many of my younger friends have moved to NYC (or elsewhere) and they have told me they don't like the overwhelming tech culture that permeate the bay drowning out the rest of the culture. I could see that happening to Seattle as well, but probably not NYC.

I can kind of understand it being like competing colonies of bacteria (each sub-culture). I think its pretty valid, but I don't mind all tech all the time ;D.