It's a question I often come across in my line of work: why does America's passenger rail system suck so much? Other countries have sleek, comfortable high-speed trains that get people from one city to another quickly ad reliably. The USA, on the other hand, has Amtrak: the money-hemorrhaging government enterprise that is infrequent, slow and unreliable.
The general suckiness of inter-city passenger rail in the United States is the result of many factors, including geography, urban density, the primacy of freight movement, and political inertia. But don't take my word for it: spend a few minutes watching this excellent, if not somewhat wonky, video on the subject.
(h/t: Atlantic Citylab)