Why does this not come up in conversation, then? Do we not think to talk about ethnicity in our fannish experience? Are we excluded by black-and-white dichotomous norms? If Indians are out there, not engaging with each other, I wonder what contributes to the anonymity.

My guess would be that it contributes a lot, but I think that the relative invisibilty in source texts makes finding each other to engage with and start that conversation even harder, because even when you (general you) speak up about a total lack of representation, I don't think it gets heard as much as a poor or misrepresentation does, so the message doesn't spread as widely, and people wind up saying the same thing, relatively quietly, each from an isolated corner. (If that makes any sense outside my head.)