Is LA that politically different than SF?
But which top college wouldn't culturally or administratively have a positive atmosphere towards immigrants, financially disadvantaged, Muslims, gays, sexual equality, or gender issues? Basically the salient topics of our time.
Peter Thiel might simply want to take advantage of the less-crowded LA tech scene, or I suspect he might've tried Austin, but even then, I don't think it's that much different in atmosphere.
Compared to SF, LA is a true big city, as close to New York as you can get on the west coast. In comparison SF is a petty small town, complete with the provincial backstabbing and all.