The lender is probably the federal government. The make the political choice to make loans without asking about credit worthiness, because we mistakenly treat university education as the only path to upward mobility. The schools abuse that social status.
If that is the case then the loan is just an unorthodox method of taxation. In that sense there should obviously be a limit to how much tax you owe to the government otherwise it becomes abusive. It also means that the government shouldn't expect you to repay the whole sum.
