Sure, you may weigh the benefits of living in SF higher than the cost of doing so, but that doesn't mean the cost differential when comparing like-with-like isn't significant. Moreover, once you have a family, the cost-benefit analysis changes in a surprising way. My wife and I are dedicated urbanites and currently live in downtown Baltimore. We could afford an awesome house in a dense urban neighborhood walkable to restaurants, bars, our daughter's nursery school, etc. But we're relocating to D.C. where a house in a similar neighborhood would cost 5x as much, and are facing the prospect of having to move out to the 'burbs (or the more boring suburb-y parts of the city).

> but that doesn't mean the cost differential when comparing like-with-like isn't significant.

That is kind of true, but it's also not realistic to just compare identical housing arrangements in very different regions. It makes more sense to compare not just median costs of two regions, but also median housing size/type. But of course, if spacious housing is very important to someone, that's perfectly fine, and it's a perfectly good reason to live somewhere else.