Terming it as a problem with Indian users is racist and hence leads to an analysis that focuses on understanding if Indians destroyed Quora for the rest of the world.
The problem with most online communities is that, as they grow the quality of discussion necessarily goes down. And given the generic nature of questions on Quora, obviously the topics that the majority community is interested in, will tend to dominate. Today Indians make up a majority of users, that majority could soon be Chinese users or somebody else. Does that make Chinese users the problem? No.
