I think this analysis is missing the main point of this kind of agreement, and that is that in the worst case scenario -- the graduate can't find employment, or income can't support the student loan payments -- this agreement should be better than straight loans. From another article [1]: "At Messiah College, students who opt for the school's ISA will pay between 3 and 3.5 percent of their future income for a set period of time. Payments are waived if a graduate's salary drops below $25,000 a year." (Of course, I don't know if this example is representative of all of these agreements)

On one hand, I could see this working for students going for degrees with less job certainty than comp sci. But on the other hand, this does seem like treating a symptom rather than the causes, like we're encouraging too many people to go for degrees that don't lead to gainful employment or self-sufficiency.

[1] https://www.usnews.com/education/best-colleges/paying-for-co...