There is not a (net) mass exodus from the Bay Area, hence the ridiculous prices. I moved to SF in 2006 and there were always people claiming it was on the verge of collapse because everyone was fed up with the high prices and crowding and was fleeing. Funny to see that nothing has changed.
“No one goes to that bar anymore, it’s too crowded!”
this is an interesting asymmetry I've noticed too. There are countless of places where salt of the earth Americana is the de facto monoculture.
If I'd go there and try to create a liberal-hippie space for myself they'd probably flip me the finger and tell me that's not the local way of life, and somehow everybody seems to agree that this is perfectly fine.
Yet when people in the valley or in a big city share a common culture they somehow have to defend themselves and painstakingly carve out a space for Peter Thiel et al. Why is that? If he doesn't like California's culture Thiel can move, end of story. Why do we have to treat him like a wounded deer?
I don't see many people in SV culture claiming to value "diversity of thought". They value diversity of culture, races, sexual identities, etc. But not thought (unfortunately).
That said, other posters are 100% correct when they write that rural America is just as intolerant, only in the other direction. And you don't see many people moving to those areas and attacking their lack of thought diversity (probably because they'd get shunned, at best, or shot, at worst).
If someone is using "intolerance towards those who hold different opinions from oneself" as an insult, it only makes sense to assume they are claiming that they are different.