«It declined after WWII (i.e. long after the so-called "robber barons") because the interstates and flying took away much of the passenger traffic and made it unprofitable.»
I'm trying to point out it also declined because the inheritors of Robber Barons focused on the comfortable and easy profits of coast-to-coast cargo over long term investments in infrastructure. Yes, interstates and advances in flight did their part to minimize the public interest in passenger traffic, but so too did giving priority of all lines to cargo and avoiding long term capital maintenance and improvements. The railroad industry has a lot of "tech debt" that they've passed on from generation to generation and it's past time someone went in and refactored that debt. Yes, some of that tech debt is the fault of the Robber Barons themselves in that the majority of what they built (using public right of ways and public eminent domain to help construct it in a very strong example of America mistaking public infrastructure as private corporate profit centers) was never built with long term maintenance and sustainability in mind.
For better or worse, there just isn't a lot of appetite in the US for creating new rail lines that would be money losers.
>We refer to the founders of the American Rail system as Robber Barons for many reasons, but they certainly did a good job of robbing from the system's own future as well.
Not sure what you mean by that. They built much of the rail network. It declined after WWII (i.e. long after the so-called "robber barons") because the interstates and flying took away much of the passenger traffic and made it unprofitable.