Stop labeling them as Madrasha because they are not. They are basically arabic learning institution where Hindu student are taking advantage over Muslim to send them to Arab country to make dough. This is another prof that Muslims are really in bad shape in India as India shirking education for Muslim kids.
Just to clarify these are Madrashas and the qualifications they offer on graduation are similar like Maulvi and Munshi (equivalent to matriculation) as well as Alim(BA equivalent), Kamil and Fazil (MA equivalent) degrees.
Majority however provide basic level education which is tahaniya and fauqiya (primary level education). Along with Urdu, Arabic and Farsi, Hadith and Quran studies which form an integral part of the studies, they do teach other "secular" subjects like science, maths e.t.c.
For non-muslim students they have an option to opt out of some of these but many infact do attend them. The management of these institutions is wholly under the ulemas. The motives for students studying (most of them who are primary level students) you are mentioning here is childish.
If these madrasshas are adding subjects like science, English, computer studies e.t.c, then that doesn't change the Islamic essence in anyway. Madrasshas are supposed to be centers of knowledge and these steps should be commended. It is high time these subjects were added.
On the other hand, there are many muslims who study sanskrit and hindu religion and the vedas and varnas as part of scholarly research. These institutions are doing a great job in creating the next generation of Indian citizens by giving them a better understanding of Islam compared to what we get from the media. They go along way in improving inter-faith relations. Hopefully, similar reform steps are being taken in Bangladesh madrasshas as well.