>As to why we require loans to be originated without regard to credit risk: if we took credit risk into account, disadvantaged groups would get student loans at drastically decreased rates.

Those are unlikely to be drastically decreased. What will drastically decrease is the amount of people, of any color, who can afford an art history degree. That is a good thing, especially for those who will be the first in their family who are going to college, and are therefore more likely to be swindled into one of those degrees in the first place.