I do remember often being frustrated when mostly useless Yahoo Answers content would appear at the top of Google search results. I never understood why it was ranked so highly. YA seemed like what Quora would be like if you were required to flunk a literacy test in order to participate.
At least Yahoo! Answers entries were short. Quora is basically the Y!A of today, but with essay-length responses that don't still don't answer the question.
Have you looked at Quora any time in the past 6 years? The answers may be grammatically correct, but the content is not much better than Yahoo Answers, and at least Yahoo Answers was funny.