This is actually what happened in parts of Westchester and Connecticut. All the executive staff were commuting from their suburban homes to their various headquarters in NYC, then they realized they could just move their office instead.
It was also the case that if you wind the clock back not all that many years, relatively few of the people working for, say, IBM (especially at the executive level) actually wanted to live in Manhattan.
Obviously the Bay Area as a whole has a problem with housing prices. (It has for a very long time but it's become extreme relatively recently.) But one of the big issues with housing prices in "prime" cities is that professionals weren't clamoring to live in them until quite recently.
Look at Boston/Cambridge as well. Teradyne was probably the only significant tech company with a major office in Boston until the dot-com/bomb and it later moved out. All the growth in Kendall Square and Seaport is recent. It's no wonder urban housing and transit hasn't kept up.
If you look at small-to-mid sized law (or other professional) firms in the Bay area, you see a lot that have 2 offices: One in FiDi, one in Walnut Creek (or somewhere similar). Guess where the partners are all spending any day that doesn't require a client meeting? :)
