Why does transportation need to turn a profit?

We have no problems dumping trillions into road repair so that GM can profit from making cars that break down after 100k miles. The amount we subsidize for a car centric culture is now turning against us, we are 70% overweight and 50% obese because we moan about walking distances longer than a driveway. They had no problems stealing farmland to build 95 and the state roads, so why not do it for railroads?

Trains long term are cheaper. But Nope! GM and Elon Musk can’t profit from it so it’s a bad idea