Interesting view, and mostly consistent with the facts. Eisenhower did see the Autobahnen and how the were used to quickly move German forces around, and pushed for something similar here that also (wink wink) helped rescue parts of US heavy industry from a potential recession when the Korean situation began to wind down. But on the RR side I don't think he was necessarily anti-passenger train; rather he just had it in for railroads generally.

Railroads that had management who actually read the accountants' reports knew back in the 1930s that passenger trains were on the way out as a general transportation mode. Some did something about it as things became obvious in the 1950s, but the ICC regulatory system made it very difficult. A few of the better-capitalized companies focused on the first class market as an advertising measure (most visibly and well-marketed, Santa Fe) while quietly getting rid of anything that didn't carry mail.

Mail is what kept most of the passenger trains running. Loss of mail contracts, especially when the PO moved entirely to air and road in the 1960s, is what allowed most to be abandoned because at that point even the ICC couldn't claim public interest in empty trains (whether by railroads driving people away, or just availability of good roads/cars and long-distance flights) any more. Followed of course by Amtrak in the 1970s when the remaining runs threatened to bankrupt a few lines.

Amusing PS to the mail issue: mail traffic (bulk, in trailers) also got some of the higher-end intermodal service going. In particular, it was the main user of Santa Fe's Super C (40 hr or less, Chicago-LA). Later on, UPS got into the game with the Z trains, though they seem to have moved some shipments back to highways (team-driven trucks) more recently as has the PO. And the PO contracts some of its traffic to FedEx. While UPS and FedEx both now use the PO for lower-priority local delivery (even on Sundays, for no extra charge!). But Amtrak doesn't haul mail despite having regularly-scheduled, "priority" service between many major cities. Go figure.