SF maximizes technological intelligence, Wall Street maximizes financial intelligence. Plenty of overlap, but the top talent stays where the rest of the top talent is.
Having technological intelligence doesn’t make San Francisco a “human epicenter” (whatever that is). I wouldn’t even call San Francisco a technological epicenter. Even within computer technology, much of the most important technological intelligence in the US is outside San Francisco: in Portland (Intel), Seattle (Microsoft), San Diego (Qualcomm), and maybe San Jose (Cisco). Put differently, what cities would be most devastating (in terms of impact on US technological capabilities) to lose early in WWIII? I’d put Boston or Seattle ahead of San Francisco.
Agreed, SF has a lot of tech companies, but a lot of them don't do things that ate very valuable for society, many are social networking/advertising.
I think consumer tech is valuable in the sense that our peace-time economy is based on consumption, and San Francisco is great at helping us consume. But when I hear the word epicenter I’m thinking “what’d put us back in the Stone Age if we didn’t have it?”
I don't think a significant proportion of the people who want to live in New York would cite Wall Street in their explanation.