I have worked in tech for 15 years, around the world, an have never met this mythical "tech bro".
The typical SF tech bro stereotype: Youngish white guy, BS in CS from Michigan, lack of self awareness, enjoys Pliny the Younger, Barry's Bootcamp, standup, rides a boosted board to work in SOMA.
(This is not meant as a critique, I probably satisfy a number of these checkboxes myself...)
A fresh grad, new to SF that doesn't yet realize he can't unironically like trendy beers, workout routines or gauche means of conveyance?
That's not a bro! You guys just needed a word for cultural immigrants that haven't assimilated yet without making yourselves sound like bitter townies, didn't you?
But you do strike a chord with "a word for cultural immigrants that haven't assimilated yet". I know one person from the rural midwest who studied CS, landed in the Valley, and ended up leaving for some midwestern company - earning less money for work he liked less - because he couldn't assimilate. He swore teaching English in Japan had been less stressful and shocking than trying to keep up with the demands and hostility of SF culture, and honestly I don't find it hard to believe.
I've had people quite sincerely tell me that there's no such thing as "Bay Area culture", just an expectation that people do the right thing. I suppose it's one of those "fish in water" situations, but I still have trouble understanding the amount of hubris required to say "oh, other people have cultures, we just have the right way of behaving".
I think it is mainly seen in SF or huge cities that's why I proposed the numbers thing. I haven't heard the same comments from Seattle for example. Also, if you live in SF maybe explicitly ask carsharing drivers and waiters about them, they will start ranting.