Amir might not realize that he is flirting with some political undertones, with his argument, but is also the same stance on the word that I've had against Anirudh'd characterization. I might have had a brief discussion with Anirudh about this a couple of years ago, and my position is the same as Amir's. It's a leap to consider the two the same, and that one is referring to the Indo-Aryan group when they say 'Indic'. Here's the etymology of Indic[1] from Etymonline, which is the one Amir is going by, Merriam-Webster on the other hand[2], as pointed earlier, accepts both views. Given that the term is listed as an adjective, and has Latin root
Indicus and Greek root
Indikos, both of which denote "of India;" might help. This might also relate to how foreigners perceive a word innocuously, vs. how the people being referred to see it. Ethnolinguistics is far more interesting.
I pointed out then, and I'd do so again, that Anirudh's classification might have a shade of influence from the nationalistic stand on the usage of the term[3]. It's hard to debate this issue, when you are arguing over the intention and context of a single word. To everyone unaware, Indic is just some extension of India, denoting 'of India' and nothing more, while some can choose to equate the word to a subset of a linguistic family and bring up divisions thereof. The only thing that separates them is probably context.