(Probably does for rock music...)
Anyway, the point is that people who value culture highly tend to live in San Francisco if they can, even if they work in Silicon Valley. (There are plenty of tech jobs in SF proper though, but generally more Internet stuff and less backbone stuff.)
And some people do exactly the opposite, because they prefer the sedate suburban lifestyle but want one of the great jobs in SF. The high-tech scene out here is really not about some monolithic suckling VC cabal attached to Stanford, it very much includes the East Bay (particularly Berkeley), SF proper (a center of Web and media innovation), South SF (world capital of biotech), and Silicon Valley, and then on down to San Jose (Adobe, etc) which isn't really part of Silicon Valley either.