In a word, NIMBYs. In many places in California, the people already living their have both the inclination and the means to tie up the construction project in

In a word, NIMBYs. In many places in California, the people already living their have both the inclination and the means to tie up the construction project in court until 2145. They don't want the construction, or they don't want the influx of commuters, or whatever. To a first approximation, the places that will accept the project happening are the ones looking for a train that goes somewhere else.