Um...what am I missing here? None of those three cities has a million people, and we're talking about a massive amount of territory going down to San Jose where commutes are not the easiest thing. Yeah, they're both drawing now. But San Fran has been winning a lot of titles lately and Oakland's won two straight divisions. If both teams aren't perennial contenders, I don't think it works.
The area has not been able to support two teams for the duration. Oakland's attendance was incredibly abysmal for almost a decade, and they had winners in that time. The fan base isn't there.