Why do Indians care about OIT/AIT

From my blog:

Razib: I follow your super feed and read your postings here and on Brown Pundits. The subject of the ancestry of South Asians comes up frequently. It seems to have a political valence that I, as an outsider, do not understand.

Can you explain it? or point us to an explanation?

My response is “British colonialism and modern-day culture wars.” I could say more, but honestly, I don’t care that much. The science is more interesting to me, and it’s a lot to keep track of. Can readers comment?

(Related: there are some Pakistanis who try and pretend as if they are descended from Persians, Turks, or even Arabs. The explanation is pretty straightforwardly summarized as “self-hatred”, though we could all elaborate on that).