While changing the system might seem simple it's actually a time consuming process that could take years upon years to tweak into something new and workable. The current system, while not very appreciated, does work and aid students as it's supposed to.
It gives them an opportunity to learn at a place they might not've been able to afford without help. The school a student attends is their choice and maybe it's unfair that they are young. That they're still trying to learn responsibility, understand the importance of applying for scholarships and grants, realize that debts hard to pay off. However, it's still no ones fault but their own if they are unprepared.
The current system does take a bit of patience to understand without big words or equations getting in the way but it boils down into something functional. Something that can be used by both parties. Maybe not an equivalent exchange but certainly nothing drastic that has loan sharks coming after you. It's a system that's workable and bearable if a person is smart about it.
As of now, changing the systems in place are projects that lack funding, time, and would be experimental in nature. What we have works and could we afford to have something that doesn't?