You can't stop a college kid from behaving badly. Nor, in some ways, do you want to. It's good to let the wild beast loose for a while. Nor should you manage a person's behaviour using loans as a control mechanism, in my view. If that's why you have them, then for me that isn't reason enough.
I don't mind a bit of debt but a lot is insane and what happens when there's a massive surfeit of demand against a fixed supply of college places is that the price of admission goes up and up and up.
So in the end the costs of the loans keep increasing.
You somehow want a limit on the loan size so that the cost is not disruptive of a person's life.