At the risk of being a bit facile, "an armpit" is what I get when reading about it. No mountains, humid summers, frigid winters, decline and decay in abundance. It's about the last place in the US I'd want to live, I think.
More than a few startups, I'm afraid the whole area needs to work a bit on its 'brand'. How many people from younger generations pretty much immediately think of the rusting industrial husks and other fairly negative things when they hear 'Detroit'? My inclination is that this would most likely happen by being so cheap that people can move in, get lots of space for not much money, and do creative things with it.
BTW, "San Fran" isn't a very current term for San Francisco.