I think the counterpoint is an interesting one: SF is an expensive place to live, and I've never been a fan of California's politics (an opinion, obviously). Meanwhile, Texas is a beautiful state with millions of people, half a dozen top notch universities, relatively low taxes and a definitively cheaper cost of living (outside of Austin proper).
I'm sure SF is nice, and I've love to visit... but there are more places to work than just there. I also find it interesting that geography plays such an important part in the startup culture when we're all sitting infront of multi-megabyte connections capable of HD video and chat.