Look, it's obvious when it's an aged degree and you can easily see that the granting of that degree has little chance to a highly paid job. What do you do when it isn't obvious? When I got my student loans for my comp sci degree, it was right at the bottom of the dot-com bust. Everyone was convinced all tech was going to be outsourced and that it was a dead end degree, foolish to pursue.
If the banks had any say in if I would have gotten loans that year, it would have been no. And I wouldn't have gone on to a lucrative career in tech.
I'm not convinced that letting loan underwriters pick the future labor force allocation is the solution.