This is not unusual for the US.
Even in Europe trains are usually more expensive than planes.
Here is what Germans say about their rail system:
Everybody who thinks rail is some miracle should listen closely to what she says. She even says people are taking long range buses instead of trains because they are much cheaper.
Why is flying cheaper than taking a train in Europe, usually? Let's find out why trains are often the more expensive option compared to flights.
djaunter.com
Why is Flying Cheaper Than Taking a Train in Europe?
"It took awhile for me to wrap my head around the fact that plane travel within Europe is often the cheaper option for getting from Point A to Point B,
train travel being the more expensive option."
This perpetual talk by Chinese members over and over and over how trains are the best method is just a myth.
Yes, if almost all of your population is crammed into one side of your country due to a desert then it works out well. However when the busiest travel distance is 4,000 km (like it is in the US) a train is not going to work out well.
Both the US and Europe having had commercial airline makers for decades serving the public need. People simply see trains as old technology especially when jet airlines started appearing in the late 1950's.