They set up booths at college registration day to catch the unwary freshman who's just turned 18, for crying out loud.
IOW, when they default, I don't feel sorry for the banks. They have no business lending to the uncreditworthy. Half of the job of lending is finding out if the lendees can pay the money back.
The problem is, it's not the banks who pay. Any loss suffered by a bank on bad debt is passed on the the bank's other customers ion the form of lower interest on their deposits and/or higher interst on their loans. Deadbeats cost us all money.