"But cancelling all student debt and then continuing to issue new debt to students that the university fails (i.e. by not putting them in a position to make enough money to easily pay it back) doesn't make sense."

That's one thing that never made any sense to me. I get it. I really do. But I've never seen any compelling, realistic answer to "And then what?". This only solves the problem of the HUGE number of people with crushing loan debt now. I get it, I really, really do. But... then what? What about the next decade? It's not getting any better.

The most important word in this is "realistic".