It's false that "no one wants to spend the money to improve it", as proven by the voting for recent ballot initiatives to fund high-speed rail and BART expansions in California, to cite just one example.
A LOT of people would MUCH rather have large amounts of public dollars spent to improve transit than to, for instance, fund wars, bail out bankers, etc.
The HSR is CA was funded in 2008. It looks like the first leg through Fresno might happen in a year or two. China went from no subway to the biggest subway system in the world in 15 years. They have 5000 miles of HSR. We have zero.
If you really want to get people off the highways, mass transit needs to be made more convenient, not the lesser of two undesirable choices.
And just for another comparison: The MVV (Munich Transport and Tariff Association / Muenchner Verkehrsverbund) serves 2.6 million people (Munich and the greater Munich Area). The S-Bahn (commuter trains) lines are 442 km, the subway lines 103 km and the tramway is 75 km. There is also the bus with 457 km on 66 lines in the city.
(I've ignored buses for the outer regions and the option to use trains to reach the city from suburbs).