I really wonder why the heck someone goes around danbooru downvoting perfectly fine images. I keep noticing negative score on new uploads again and again, like this one here. WTF!?
Well, some comments in the Q images has the merits to being downvoted, but I would not mind about that too, because some discussions are followed and liked by a lot of users, so they up/down voted the comments that they consider adecuate/inadecuate for the image.
I don't mean questionable rated, but that contain socially-questionable subjects. Bestiality, rape, etc. There's someone going to images where they don't like the subject of the image itself and downvoting the entire comment section regardless of the discussion.
But in that case (Aside from the main topic here), is the criteria of the users and knowledge about that situations and topics, most of the discussions ends always in a wannabe fights between "Open minds" and the "Internet moral defenders", so even if the comment was very accurate, we are in Danbooru and the discussion is about an image related to sex.
Some users doesn't know how to moderate his/her feelings in the internet.