The SF/LA route has an even bigger problem: once you get to LA, then what? There's not really enough transit in the LA area to get where you actually mean to go

The SF/LA route has an even bigger problem: once you get to LA, then what? There's not really enough transit in the LA area to get where you actually mean to go, and that's almost certain to be true even if all the current transit projects finish. The Bay Area frankly isn't much better. You'll very likely to need to take a car (maybe an autonomous one) from the end points. And given that, flying seems even better. There are 3 big SFBA airports and 5 in the LA metro area; direct flights between those are more likely to get you closer to your endpoints. The more legitimate case for CAHSR is really opening up the middle of the state. But that could have been done much cheaper.