> Those who can't write/read their own mother tongue are the product of the aforementioned linguistic apartheid

You have two options:

a. Teach them a language they can use almost anywhere on the planet. A language that documents most of the planets knowledge.

b. Teach them a language they can use in their geographical district and almost nowhere else.

The powers that they'd be better served by (a). You might think (b) would have been a better choice, but implying that (a) is akin to apartheid is ridiculous.

If I'm forced to use the word "apartheid" to label one of those, I'd point to (b). To teach the poor of india a language that handicaps them compared to humans of the planet who take path (a) is to limit their opportunities and keep them "in their place" in their little geographic corner of the world.