Maybe Quora topics belong to WD, but Quora questions don't. Just try this search https://tools.wmflabs.org/mix-n-match/?#/search/balloon to see plenty of ad-hoc questions that can't possibly belong to WD. Here's one https://tools.wmflabs.org/mix-n-match/?#/entry/22531602 and even more, some are already deleted on Quora! https://www.quora.com/topic/When-a-Balloon-Is-Rubbed-with-a-Sweater-Which-Charge-Does-the-Balloon-Has
Somehow I also don't think MOMA paintings belong to MnM. What do others think?