Denver to Chicago is about 1000 miles. Leaving my home in suburban Denver, driving to the airport 2 hours before my flight, Flying, and then taking El to downtown Chicago, I can leave my house at noon, and eat dinner at the Palmer House. On Southwest Airlines, my fare is 100 bucks. Southwest will run that same plane back and forth between Chicago and Denver 5 or 6 times a day. Yes, it cost them 50 Million dollars, but they can sell 1000 tickets per day. That's $100,000 per day, charging steerage fares. 300 days a year (it's in the shop some) generates $30 M. Yes they pay pilots, waitresses, baggage, fuel-but that machine will last a decade.
If I take Amtrak, I head downtown to Denver at 5 PM or so, check into the train, get into my sleeper, and have a relaxing glass of wine, read a book, and fall asleep. I awake in eastern Nebraska. Assuming no delays, I arrive in downtown Chicago in time for dinner at the Palmer House the next day. Amtrak costs 400 bucks-though if I split the sleeper, double occupancy makes it around 300 bucks. Going coach is around 100-the same as southwest, but it's a dehumanizing experience. I don't know what a passenger train costs-I'm guessing somewhere between 5 and 15 Million. But it carries a few hundred a day. And there's 1000 miles of track to maintain.
Lets say the train went 200 miles an hour across Nebraska instead of 60. I'm eating Breakfast at the Palmer House. But maintaining 1000 miles of track to a level that trains can go 200 MPH is very expensive.
That's why Americans do not embrace rail. It works Boston to NY, NY to DC. But even Boston to DC is a slog compared to air travel. I don't care about California because those pantywaists deserve whatever misery they get.