SF to Gilroy could be done in under a decade, which then would be connected to LA once that track was done.

California is messing up the HSR project by not getting SF to Gilroy and LA to San Diego completed first. Sacramento to Nowhere is a PR blunder for the state.

It's because that's the only places where they can actually build. The peninsula is full of millionaires that hate the idea of HSR. ("But I don't it at grade!" "But I don't want it in the air!" "But I don't want it in a trench!" "But I don't in a tunnel!" "It's all moving so fast!" "Can we put an HSR to stop every 2 miles?")

https://www.paloaltoonline.com/news/2015/10/14/palo-alto-bla...

http://www.smdailyjournal.com/news/local/high-speed-rail-met...

The BART extension to San Jose was first voter approved in 2000. Many years and bonds later it's closer but a San Jose BART station still does not exist.

I'm not sure CA could do SF to Oakland by HSR in a decade.

https://en.m.wikipedia.org/wiki/Silicon_Valley_BART_extensio...

The only reason it could not be realistic is that California is politically dysfunctional and unable to solve problems. Nearly every other industrialized country has a rail system that connects cities and helps commuters. It is totally possible to accomplish.

It is not a realistic short-term solution, but maybe a good long term move? Your comment makes it sound like it isn't a reasonable investment at all because it won't return in the desired timeframe.