You might want to sit and think a while about what our railroad system might be like if the government had not subsidized the automobile.

I'm not in a position to comment on US case histories. I can comment on my local situation: before the 1960s, Sydney (Aust) was reputed to have one of the best light rail (tramway) networks in the world. In the early 60s, this was competely ripped up to make way for the great god Automobile. Sydney now has very bad traffic congestion with consequent health and stress effects on the populace (including me). Even a few years ago authorities were saying we have air equivalent to a dozen cigarettes a day per person, and it's definitely gotten worse since.
(Hey - if a visitor from Texas tells me the city 'is not particularly pedestrian friendly" - I listen!)

Of course, this is world wide, and not as bad here as LA, Bangkok, London, and so on. (And parts of the larger city area are in fact well serviced by trains and buses). However, the roads of this town were built makeshift, about 2 centuries ago, and are narrow and disorganized. They are not built for heavy traffic flow! And yet - successive governments sold off valuable and critical infrastructure and prostituted the city to the various car industries. Only now do they realize the magnitude of the problem, and plans are in place to build one or two tram routes around the city central. Small mercies ..

And of course (as you might point out) people - the consumers - went along with it all, and if anyone is responsible it is them. That's the demand-supply argument, and yes it's valid - up to a point. But the bottom line to me, is that it's the mega-profit system, which intrinsically must have no growth boundaries, that initiated this situation. People then respond as people do - by adapting themselves to an inevitable circumstance, and making the best of it.