I'd add two more bad things about the valley: faddish thinking / groupthink, and completely insane costs. I can only speak second-hand, but the Valley strikes me as very much a bubble with its own internal echo chamber and groupthink. If you're in the Valley, you are likely to get sucked into chasing trends that everyone else is chasing instead of finding a unique niche nobody's thought about. And the cost of living is simply absurd: think Manhattan except car ownership is an almost must-have.
I also hear that the availability of funding in the Valley is overstated. Early-round funding is scarce, and funding might be even more faddish than the startups themselves.
The advantage of the valley though is the talent pool. It's fresh, large, and highly skilled, though perhaps a bit fickle as the interview mentions.
Finally, having lived in Boston/Cambridge, I can mention one distinct disadvantage of that particular place: it's somewhat antisocial and has a conservative investor climate. I found it a somewhat stifling place to live. People don't have friends. They have colleagues. And investors there tend to be more risk-averse than California.
If I wanted a big startup hub that is not the Valley I would honestly pick Austin: lowish cost of living, lots of tech talent, nicer climate than the Northeast, and more fun than Boston. New York might be a possibility too, as it's more fun and diverse than Boston and probably less conservative.