Because they can't afford to live in SF- which is largely constrained by physical barriers to growth.

I do agree anti building regulations are bad and somewhat at fault but it's not an apples to apples comparison by any means.

Rich people want to live on the west coast because it's beautiful and the weather is pretty nice. In fact I wish I could live on the west coast but could no longer afford to once the baby came along and my wife and I decided to go single income.