I still cling on to the quaint idea that "upvote" means "adds meaningfully and coherently to the discussion", while "downvote" means the opposite. So not "I agree with this" or "that made me chuckle" but rather "this enhances the conversation" - and especially if it's a well written argument I disagree with because that might make me learn or rethink my position. Humour in a well argued point is very welcome, of course.

Wish and reality aren't in alignment here but some places like HN or /r/AskHistorians are my refuges.