One of the things missing in this article is that the reservation system by design results in quota students typically being less prepared/qualified. These students then enroll in, say, IIT, and many of them perform poorly due to, well, lack of merit. And this poor performance contributes heavily to the lack of continuity on to further, and higher studies.
Who is responsible to fix this? If institutions were stricter on reservations, they would simply exacerbate the problem. If institutions were mandated to provide above-and-beyond resourcing to help poorly prepared students they were forced to accept, that's a pretty onerous burden.
The solution isn't finger-pointing at higher education/academic institutions or doubling down on reservations -- it's to kill reservations entirely and double down on earlier education subsidies for historically disadvantaged groups.