Many people just vanish after they get their license. It's crazy. They spend all this time and money (and I'm talking recreational not those on a pro track) and then it comes to a halt.
I believe minimums required to keep the A/C overnight are one reason. Want to fly from Dallas to Houston for the weekend? Schools want 5 hours per day on Sat and Sun. Which is 2x the actually flight time.
I get the need for profit but it does discourage rentals.