This doesn't solve the problem. If schools have a ratio N students per teacher, then at most 1/N students can expect to become a teacher. This works fine for

This doesn't solve the problem. If schools have a ratio N students per teacher, then at most 1/N students can expect to become a teacher. This works fine for things like B-school of CS where there is heavy industry demand for the credentials and less than 1/N students are trying to be teachers. But for other departments, especially humanities, there is essentially no private sector demand for that credential at the graduate level. This means that almost all grad students are aiming to teach, and since one teacher can teach many students, the majority of them are destined to fail.