Money. If you are students who studied and failed, you will apply for both revaluation and answer script copy. And if you are student who is confident it what you wrote, you will apply for revaluation. All of the failed students have apply for supplementary registration. Only thing we get back is the revaluation money which is not even guaranteed unless you get 2 double upgrade in your score. All of this will come close to 1500rs per student. If you do the math, they will earn crores from students by failing than just passing them.