OkCupid used to map those important things people don’t talk about via thousands of multiple choice questions, and you used to be able to build a search filter from the answers you’d accept. Then MatchGroup/capitalism/puritans wrecked it. I don’t know if there exists a good dating site anymore.
Consequence of lack of onboarding. Would be easily fixed by popping up instructions for voting and feed shaping the first time a new user votes.
Quora may be exacerbating the behaviour by automatically blocking topics when you downvote questions. They also downvote a question for you when you only want to report it for something. The downvote remains after the reported issue has been corrected.