The California project didn't have to be sold the way it was - but that was the whole point, get the boondoggle started.
They could have spend a fraction of the money on improving the capital corridor and the Santa Barbara - San Diego corridor instead, but that wasn't sexy enough.
It got sold that way because of CA's slightly weird proposition system.
There's no real political willpower for transit in California as a state; it's all located in some of the cities, which are plodding along relatively slowly but consistently (the San Diego Trolley is miles more than it was 20 years ago).
They could have spend a fraction of the money on improving the capital corridor and the Santa Barbara - San Diego corridor instead, but that wasn't sexy enough.