This kind of goes back to pg's "Cities and Ambition." Even amongst top CS departments, I think the atmosphere of the surrounding area does influence what the students want to do with themselves. Entrepreneurial spirit isn't necessarily something that's ingrained into CS students by default; students need to be exposed to it, and more importantly they need to see how far they can go with it (which you would see constantly in CA) before they start taking it seriously.

> I supposed I just assumed MIT was the same (as Stanford) because the CS departments are comparable.

Comparable != same. They're both good, but they're different.