This is very well put, but I don't think San Francisco is exclusive to this, especially in California. I'm sitting in Orange County right now and every thing I could want to do is at most an hour and a half away. Twenty minutes to the ocean, and hour and a half to Lake Arrowhead/Big Bear, an hour from Los Angeles and an hour from San Diego. An hour away is also the desert (amazing for camping.) Hell for anyone who's still into CES Vegas is four hours away, three if you go a little faster than you should.
Although I get one of the biggest appeals to SF besides the flexibility is the large tech industry, but you'd be surprised how many meetups, companies and stuff you can get to because of the close proximity to two major metropolitan cities, and Irvine (believe it or not) is huge in tech but just business in general here.