Both good points that I forgot to mention. I implicitly assumed most people would eventually move away from SV, but if you plan to stay there your whole life, then you'll have a much more difficult time buying a home and/or retiring. And having children adds a whole new dimension of financial difficulties.
It also adds a bunch of social difficulties, unless you try to pull of the entire make-bank/move-elsewhere cycle before they reach elementary school age. Once they are in school, they start making their own friendships and relationships, and it becomes much more impactful for everyone to make that move to the new low-cost area, leaving everything they know behind.
