while a debatable point, with or without the heavy government regulation, i doubt that few railroads would have survived beyond the 70s anyway....
my favorite road, the New Haven, if stripped of its passenger service, was essentially one overgrown switching yard as its longest path was 250 miles...combine that with the declining New England industrial base that was its lifeblood, and the Connecticut Turnpike and airlines that started sapping away its passengers, and the New Haven was likely doomed anyway...
as to modern passenger trains, i have ridden Amtrak, and the on-time problem will never be solved as long as they are treated like the junior partner by NS, CSX, et. al...my memory of Amtrak from 2005 was sitting for close to 30 minutes...supposedly, we had to defer to a slow CSX freight that took forever. (also, it should be noted that if an Amtrak train is derailed on CXS or NS tracks, that commuters are to sue AMTRAK, not the host roads!)
As to Acela, it is one more lame revival of the Talgo train concept (every 20-30 years, some bright boy somewhere gets the idea of a pushme-pullyou high-speed passenger train).....The New Haven rails played host to the concept 4 times since the 1930s and each time, the concept was found wanting for American travellers....
the 1930s saw the Comet which was fast, but lacked flexibility for any unplanned passengers (in that case, the NH had to run an extra train behind conventional steam, with the unplanned expense...and they were in bankruptcy at the time)
The 1950s saw THREE such trains attempted by NH management (who ran the road into the ground)...only one lasted for any length of time because it was essentially a gussied up RDC (Rail Deisel Car) setup....the others were off the rails in less than two years....
the 1960s saw the TurboTrain on the rails (which by that time were Penn Central rails) and that fiasco was an unreliable piece of junk, and gone within a few years
and now the Acela....wow...some people refuse to learn from the past..that is why it keeps getting repeated....