Re: Los Angeles to San Francisco route comes in at $6bn
The problem is not if they research that technology and try to get past usability issues.
The problem is if everybody just wait for it to become feasible, while the rest of the transportation system is hopelessly outdated and slow. High-speed trains are an existing working solution, using a proven technology. Why wait for a more futuristic one still in its infancy?
There could be some resistance form airline companies that may not like shorter routes flights becoming noncompetitive against the trains, as it happened in many countries that deployed high-speed trains, and may want to delay the inevitable.
But the US had many of the most advanced trains until the 1940s - then modernization stopped, and they started to lag behind not only Japan and Europe, but China as well. Rebuilding a railroad infrastructure will have more benefits than bailing out banks and insurances went bankrupt due to their own greed...