What kind of reform?
There is so much bad research because there are too many researchers.
For myself, I think I am smart enough to have worked on a PhD in economics but not smart enough to have done anything worthwhile or to have advanced the field. I am certain I would not have. Then in the face of this massive student loan debt I would have produced junk research and try to game the system to make the investment worthwhile. The incentives are all ridiculous in the current system for most.
The idea politicians will cut student loan money in order to produce better scientific research would be a good way to optimize for losing an election.
Personally, I don't think there is a way out. If anything it probably just gets worse.
PhD is not paid by a student even in US, it's all scholarships.
The usual critique of academia is that people are expected to publish a lot (which creates wrong incentives) and that nobody really accesses quality of the publications (which gives opportunities to cheat). At the same time there is huge PhD overproduction, which creates competition.
I don't think the problem is that people are working on wrong problems, the problem is how they work on problem of their choice and why.
I also don't think there is a simple fix to this problem.