It's less likely that those people are truly independent, and more likely that they simply brought the orthodox beliefs of their countries of origin to the Bay Area.
That’s a good point, although I would still maintain that they constitute a different “type” of person than those that reside in their country of origin, because most people don’t uproot their lives to move between countries. Whether or not that correlates with being more of an independent thinker, I don’t know.
There are millions and millions of people streaming across our border as you read this. Perhaps people moving between countries (or at least, from certain countries to certain other countries) is more common than you think.