Previously forums were mostly highly categorized and discussions had to be kept on topic as going off topic was considered incredibly bad etiquette. With yahoo answers there was only a few days for answers to post before the question asked had to judge best answer. Irrelevant and off topic responses were deleted as spam.

Since Reddit, and the way Reddit is, posts end up being buried after a few hours and if a discussion manages to start you can guarantee it will be diverted in the responses. This isn’t even restricted just to conversation on important conspiracies, such as what we need to do about the Jews (which would quickly get deleted anyway). Even some random kid asking for homework help on the Norman conquest of England will end up getting comments diverting the discussion to Putin and trans.

This has meant that it encourages people to learn to engage in disjointed and divergent thinking- previously a sign of mental disability.