At the beginning, Quora was heavily focused on Silicon Valley. It had a bunch of Silicon Valley VCs and other notables providing content, as friends of the founders.

As far as I could tell, that made it much prized among that set of South Asians who were either in Silicon Valley or desperately wanted to be. It led to some very unfortunate culture clashes.

Its appeal to India seems to have broadened from there, and it still seems very popular.