Freight is the rail profit center not people. HSR is not a business model but a political one.
I haven’t seen any real studies accurately estimating ridership between LA >SF. ie. who would be traveling and how many trips, frequency. We already can get a pretty reasonable number based on airline trips/day.
Plus, what do you think airlines will do if the rail magically becomes competition? Lower prices, to keep passengers. I haven’t seen this discussed in the rail argument.
Next, HSR in SD would have some serious engineering challenges through hills in the current proposed inland route. Not gonna happen.
San Diego can’t even get its act together for a train direct to the airport or even the fairgrounds.