Colleges then took that massive influx of government sponsored cash and put it to work funding their bureaucracies, building an endless parade of buildings they didn't actually need, significantly boosting professor pay, and accumulating substantial endowments.
Meanwhile the actual education - their product - did not get more valuable. At a time of terrible economic performance, with 14% real unemployment, falling incomes, and lack of jobs post graduation, clearly the cost of an education should have fallen by quite a lot. It didn't because of a guaranteed loan back stop.
There is talk now that students should pay the same low interest rates on their debt that banks pay when they borrow money. If that is put into effect, all it will do is accelerate the debt accumulation. It'll enable students to borrow more, and colleges will accordingly charge more. This government fueled scheme can only end in tears (bailouts).