Allow borrowers to default on student loans. Then banks can charge an appropriate interest rate for the credit risk of the borrower, based on pursued major (among other things).
Very few students would qualify. Most of them have no credit history and little to no income. If it were easy to default, the entire system would collapse.
Obviously the impossibility of defaulting and the ease of getting loans feeds the problem, but what you are proposing would destroy the system rather than fix it.
Very few students in worthless degree would qualify. Engineering and medical degrees would do much better because good students would not default as the degree is part of what drives their job.
