> I mean this in as polite a way as possible, but why wouldn't established companies like Stripe just fuck off to another city entirely?

To be totally blunt, I also suspect a large part of it is that the founders would like to be in the bay area.

I don't mean that as a slight either - I think if you're spending a good portion of your life on something, you might as well do it in a place you enjoy spending time in!