highspeed rail through earthquake country is about the dumbest thing I can think of to waste more money
It's far worse than that. Most of the coastal region soils are either highly erosive or unstable clay. The latter is expansive with seasonal changes in moisture. The system would require constant adjustment to keep the trains from tearing apart on the track. I cannot imagine a worse place to build such a track unless with the exception of tundra. Even a swamp would be more predictable.
BART was expected to cost $792 million for the total system. It became a construction union cash cow and a gold mine for corrupt suppliers providing dimensionally-unique materials. By the time it was done the cost over-run was 200%.
This disaster will be far worse because in addition to corrupt unions we have a bottomless environmental pit looking to get its cut of the action. Just look at the current rebuild of the Bay Bridge. This project's backers will claim that this project is "too big to fail" because they're looking to use public money to subsidize their real estate investments. It should fail now before a lot more money is flushed down the dumper.
Putting a high speed rail through fruits and nuts country is a bigger problem. Many nuts will find getting hit by a 200mph train and disrupting the commute of several hundred people irresistible. Cal-train already has a steady stream of suicides.