Stack overflow is pretty popular. Although their recent attempt to "be nice to new users" (which wasn't necessary before, and coincides with the quality of answers rapidly approaching that of Quota) suggests that this won't last forever.
It was absolutely necessary. It isn't a "meme" that SO community has hostile users. I hand out a lot of votes when browsing SO because so f many people don't really deserve the downvotes.
Do you perceive Quora to have higher or lower quality answers? I'm having trouble parsing what you meant to say.