I think they're hoping that eventually, investors will get tired of paying the high salaries needed to locate their engineers in the Bay Area (or salaries won't

I think they're hoping that eventually, investors will get tired of paying the high salaries needed to locate their engineers in the Bay Area (or salaries won't increase commensurate to cost of living, and they will stop finding engineers willing to move there). Whether the city's culture or the tech community's attachment to the region will break first is, of course, an open question.