[ponker]

There are two criticisms here: one is that Quora is a bad business, and only operates because its CEO funds it, and second is that it is a bad source of information. The first is definitely an unanswered question at this point: revenue is low but the site has a vast amount of evergreen content which ranks highly on Google -- they have a ton of traffic but it's not clear to what extent they can monetize it.

The second is a matter of opinion, and whether you're looking at the average content or the best content. There is great content on Quora but the average question/answer is of course absolute dogshit.