Also, Central valley is not just an agricultural place: "On less than 1 percent of the total farmland in the United States, the Central Valley produces 8 percent of the nation's agricultural output by value: US$43.5 billion in 2013." From https://en.wikipedia.org/wiki/Central_Valley_(California)

Also the California HSR project includes modernization of connecting services. Do you consider Caltrain to be public transit?

It does not mean “available to the public.” You can also buy a plane ticket at Haneda and be in Kansai in less than 90 minutes. Japan Rail isn’t any more “public transit” than ANA.

Most other uses of the qualifier “public” are not this limited. e.g. public infrastructure, public art, and public libraries only requires that it is available to the public without major hurdles or restrictions, not who operates it and for what purpose. In my books, transit is no different. If a transit is available to the public it is public transit.

In fact there are many airlines which I consider public transit. Including domestic air travel in Iceland and Greenland (and even between Iceland and Greenland) is public transit.

"a system of trains, buses, etc., that is paid for or run by the government"

The area around the current Amtrak station is actually quite walkable, with some transit serving it (I’m not so sure about the planed HSR station north of downtown, though hopefully they’ll make some improvements before it opens in 2030).

And if you live in SF or LA and are going to Bakersfield to visit friends or family, that won't be an issue at all. And Bakersfield will likely densify a bit with HSR. And maybe it'll cause higher ridership on the currently limited local transit options, allowing them to expand routes and increase frequency, increasing their usefulness to the local area.