The private railroads got out of the passenger business for economic reasons. Air passenger transportation was taking away their patrons.
After Reagan deregulated the Airline industry there was no possibility of resurrecting rail travel. The airfares fell and their was no way the railroads could compete with the prices or the speed of airlines.
One of the major problems with high speed rail service is that most of the plans include the use of pre-existing commercial rail lines.
To get the agreement of the owners of those lines the guberment must agree that the passenger service will not impede freight service. This means that a passenger train will be sided to allow a freight train to pass.
Good does it do to have a train that can cruise at 75 mph if it spends a half hour here and a half hour there sitting on a siding waiting for a 200 car coal train to pass by
To me high speed rail would require a new set of tracks purpose built to support a 200 mph+ passenger train. That means high banked curves and high maintenance (something government is not particularly good at).
79mph is hi-speed???