Conceptually it’s a fantastic idea- who wouldn’t prefer a nice train ride to the shitshow that is LAX or similar hassles of short-haul air travel. But implemented horribly, and at a significant disadvantage… to the leverage of large landowners and other “stakeholders” due to CA’s Environmental Quality Act. So it’s been squeezed on all sides - expensive consultants to negotiate expensive land purchase deals while continually fucking with the alignment to appease local jurisdictions, politicians or rich folks (the aforementioned large land owners, homeowners in Palo Alto, Atherton and other enclaves fighting rights-of-way, noise, perceived fears of traffic, etc..)