That's definitely not true. Just look at the ACA.
> California's high-speed rail progress—its proposed San Francisco-to-Los Angeles line remains the only truly fast train project in the country—is the exception that proves the rule; that state's size makes it no example for the rest of the nation.
Yeah let's just pretend that California's train to nowhere is an example other states should emulate.
We can't build high speed trains because: (1) the government is corrupt, incompetent and beholden to interest groups and (2) the public doesn't really want them.
The best example of public transportation the US has is probably NYC and it really isn't all that great. It's dirty, slow, unreliable, crowded and surprisingly expensive. (at 100$/mo owning a car in almost any other city in the US is cheaper)