Thing is that being one of those getting in the way of bad behavior is not rewarding nor favorable. No one goes and tells the downvoter good job on making this place better if they've been using it well because they don't want to get involved in unnecessary drama and potentially in the sights of the downvoted user looking for retaliation.

The fact that downvoted rewards go to everyone is not something everyone notices because it's so small. If it was just us two posting on Hive and I'd self downvote my posts because I felt they're too rewarded compared to yours then the amount I'd downvote would directly go to your posts, thereby increasing your pending rewards by that much. However this is not something people notice due to the very limited amount of rewards that do get downvoted in general.

Just a few weeks ago I went and downvoted a user that was posting 2-3min clips of one event she performed on to make it last for 2 posts per day for 2 weeks all getting the same voters to a sum of $30-60 in rewards with 0-3 views per clip on youtube, 0-3 genuine comments per week on her posts and 0 comments of her own in over a month and all I got back was hate and drama and some people losing their minds in my posts about my actions. Why should I spend more time protecting the reward pool if there is nothing but drama and a bad reputation to gain from it even if uncalled for?

That's one of the big solutions we have to fix without making it so that people start overusing their downvotes for personal gain.