You have missed a lot of what i said/implied. First i used the phrase "Indian Subcontinent" (https://en.wikipedia.org/wiki/Indian_subcontinent) which geographically includes much more than the current nation state of India. Second, the linguistic diversity in the Indian Subcontinent is thousands of years old, well predating the arrival of Muslims/British into India. In fact, the modern Indian state lines were drawn based on linguistic identity which has always existed. So i am not arguing from the modern Indian state pov but quite the opposite.
Your statement that Sanskrit did not originate in the Indian Subcontinent is controversial and is not settled. But regardless, there were groups who had Sanskrit as their lingua-franca and who specialized in orally transmitting and then writing down their own (and borrowed from other cultures) philosophies and worldviews. The other linguistic groups in India did not do it to the same degree and hence you have the current situation where it appears that all knowledge only came through Sanskrit one-way. This is the fallacy that i am pointing out. Note that this is quite apart from what the content of the Sanskrit texts themselves may/may not convey; that is a different matter and has to be looked at through a different lens.
Your statement that Sanskrit did not originate in the Indian Subcontinent is controversial and is not settled. But regardless, there were groups who had Sanskrit as their lingua-franca and who specialized in orally transmitting and then writing down their own (and borrowed from other cultures) philosophies and worldviews. The other linguistic groups in India did not do it to the same degree and hence you have the current situation where it appears that all knowledge only came through Sanskrit one-way. This is the fallacy that i am pointing out. Note that this is quite apart from what the content of the Sanskrit texts themselves may/may not convey; that is a different matter and has to be looked at through a different lens.