The problem I really see is that we've dug ourselves a big hole. The safety net created for the banks were done to ensure that everyone could get a loan. Banks were "worried" that people would default on their student loans and run away with the money, even though this hasn't happened or is really rare. There was an unfortunate side effect that this incentivized banks to give out riskier loans. Couple that with telling everyone to go to college, kids that don't know what they want to do, and schools that are also seeking a profit, and you get a pretty messed up system.

The unfortunate part about this, is that I believe that if you remove the protections on the loans, many students now WILL default, because they have too much debt and are incentivized to do so, if they are one of the larger loan carriers. I'd say "bite the bullet, and that's what banks get for giving out risky loans" but we know that's not going to play out that way, especially since the gov owns a fair portion.

Making tuition free is nice, but the generation that took out loans isn't helped AND this does not reduce the college price problem. The price was inflated and there is no reason for them to decrease it. Kind of a parallel to health care here. That's the cost. I like this idea, even if I have to pay back my large loans, but I think the fundamental price issue also needs to be solved.

Giving a portion of your earnings is a decent method, but you already bring up the problem with that. And this also doesn't solve the price problem, in fact it encourages the price to keep going up. (We can even tangent into how schools are over charging gov for research, but I'll leave that for another comment)

Whatever we do, somebody is going to lose. And that's the problem with bubbles. We need to, as a society and government, decide who is going to lose. Problem is I think the majority of people think the banks [gov] should lose, for giving out such risky loans. But I don't think many politicians would agree. I wonder what the economists say.