You are entirely looking at India with US legal system lenses. In India, the political system is not dominated by lawyers i.e. the politicians don't have a legal background as much as they do in US. Public prosecutors don't routinely run for elections and hence have an interest in promoting themselves as "tough on crime". AFAIK, terrifying the defendant with disproportionate punitive threats and forcing him/her into a plea deal is not an issue in India. There, the problems are more around the legal process taking simply too long due to inadequately funded institutions, outdated laws and generally a less agile system (poorer country), rather than an overzealous application.
That said, both India *and US* do have arbitrary application of law - due to different reasons and cause different sets of problems. Corruption is of course more in India, as you would expect in any country with its per capita income. Yet, I'd say that far... far more people are put in prison in US due to arbitrary application of law than in India, even though the due process is said to be much better in US.