> If the student loan default rate is high, they are accepting too many.

It's fun to think about how screwed up a society would become if it did simpleminded, authoritarian things like reduce the number of seats for education students because teachers defaulted on their student loans at a higher rate than business students, and opened up a corresponding number of spots for business students. There are so many factors affecting that default rate other than society's need for graduates of a degree program...

Here's an idea: make sure people who are intellectually capable of succeeding in a degree program can choose the major they want. Support them financially if they need it. Full stop.

> I also advise that we do a far better job of publishing and thinking about career opportunities and satisfaction. Maybe even to the extent that schools should seriously consider whether it's responsible to accept X majors.

So much of what you're talking about already exists.