I think requesting the most charitable reading of something that starts from a decidedly uncharitable position is an unfair request. If cscurmudgeon wanted to have a real conversation about it, they could do their own research; this information is pretty easy to find. In this thread, there's a link to a survey of Dalits and Shudras in the US where they report experiencing widespread discrimination. Instead, they came in throwing rhetorical bombs. That's not the behavior of someone who wants to have a reasonable discussion, it's the behavior of someone who wants to derail the conversation using the language of the culture war they're claiming to oppose.