If lenders didn't expect to be repaid unconditionally, they would be less likely to lend money to college degrees that were likely to be financially worthless. This is as it should be. Before the modern financial aid situation, some people still managed to get degrees with more of a classical academic focus (i.e. without regard to market considerations). There were fewer of them, but then the odds they had to go work at Denny's afterwards were also probably lower.

As someone with degrees is math and physics, I used to think this. I don't anymore. I think that those fields offer many opportunities to examine and analyse ideas, and that is important.