Regardless of how you arrive at your conclusion I think most people would be willing to compromise to that. Repayment as a % of income for no more than 2 decades, then dismissal regardless of any remaining balance.
I disagree on merit however. Your argument is more collective investment into a person's training deserves a more proportional repayment but no outcome of specialization guaranties financial success, which is the fundamental defense of universities right now. And as we see today, tuition costs, and enormity of potential debt dissuades many, many of potential students. In actualization; the western worlds perpetual failure to produce enough doctors - which is immediately contrasted by Cuba's training and exporting highly skilled doctors, so much so that it's commonly phrases as Cuba's #1 export. We can only conclude that removing the private financial burden (that student loans create) better facilitates conditions for a collective surplus of professionals.
This is of course presupposing that we both share the opinion that having enough doctors is a good thing worth collective efforts to incentivize, rather than letting our collective fortunes play out to the, scientifically unsupported, invisible hand of the market.
In other words, if your position is that society should have enough doctors; then working backwards from the solution reveals that your strategy is detrimental to your stated goals. What's more important to you?
Beyond this specific example, no person, business or institution should have any protected right to gate keep, financially or otherwise, the culmination of our collective human experience, the summation of our ancestors, our birthright, that we recognize as knowledge. No one owns Nikola Tesla's contributions, we all do. We all make up the leading edge of humanities growth into the universe (you can visualize it like bacterial growth in a petri dish.)
Newly uncovered information (not discovered; electricity - and everything else - already existed before we could describe it) be it used to make products, such as medicines and/or intellectual property, or not used at all, should only be protected for ~ 20 years and then released into public domain, thus protecting the incentive and reward of innovation, but not allowing avarice because some people combined two or three existing technologies together in one package. Well done, sure, make yr money but keep innovating apple, wtf.
Which would make art school a rich person's sanctuary and universities no longer institutions of learning but job training. Which would be entirely in line with neoliberalism, why would corporations want to shoulder the cost of training their own employees?
If the study of culture and the humanities is paywalled then cultures and the humanities will all suffer for it.
Rich people can't make good art. It's not possible. They aren't coming from a relatable position. When I say I'm broke as a working man, that is an entirely different things than some shareholder saying it. I mean I don't know how I'm going to eat, they mean they don't have physical cash. The conditions the majority of us live under come with inherent risk and danger, risk and dangers that are removed from the opulent, that's why they're seen as out of touch.
A world of rich people cosplaying as artists is a world that only produces motivational posters and corporate desktop backgrounds. Just nuke us already, ffs.