He thinks SF is multicultural? By that standard Oakland must be Africa.
Also 'Africa' isn't very closed off to the rest of the world contrary to what you may believe. Things have changed over the past few decades.
If you're going to generalise you might want to visit Africa before comparing her to something else, or mention a city that is a more apt comparison to Oakland.
Of course that isn't the issue where an entire continent is compared to a small American town...
Edit: Oh I see, of course I have never visited Oakland so I do not understand what is said between the lines. Unless the implication was a small town is as diverse as a continent in some kind of hyperbole.