Why hasn't a simple solution of allowing people to discharge these loans in bankruptcy been considered? E.g. retroactively for borrowers before a certain time?

Why hasn't a simple solution of allowing people to discharge these loans in bankruptcy been considered? E.g. retroactively for borrowers before a certain time? I still don't like it, but at least it helps people with $100k in loans who cannot get out instead of giving them a tiny insignificant boost, and doesn't give free money to people who don't really need it?