If the issue really is that SV specifically needs more people to start companies, and having them do so elsewhere isn't possible or desirable, it seems like a f

If the issue really is that SV specifically needs more people to start companies, and having them do so elsewhere isn't possible or desirable, it seems like a first cut at solving the problem could be made without even changing visa regimes: just institute a program to convince more people from elsewhere in the U.S. to move to SV and start companies. With >300m people, most of whom don't yet live in the SF Bay Area, that's already a pretty large supply to draw from.