I am MAJORLY against disabling downvoting. This results in VERY toxic comments and content being pushed to the front and click bating content, which is what was witnessed on YouTube and Facebook, and is still a major problem. This is because youtube and other sites measure popularity of content not just by upvotes but by interaction. If you click on and/or comment on something, that's interaction. Youtube does not care about the quality of content and comments, so long as it is interacted with and shared. This means that inflammatory comments and content and click bate get lots of angry comments and rage clicks and click bait gets clicked because it's click bait and it registers and popular content that will generate lots of interaction so it gets pushed to the forefront. On reddit this kind of content gets largely weeded out by a quality check, downvotes. While no system is perfect, this allows the community to say "no, ok, just because I clicked on this and maybe even left a comment, this is NOT good content, and should not be shared with others." It also is a natural scam and spam filter that allows the community to quickly shoot down anything that is obviously spam.
Youtube comments were extremely toxic for this exact reason for a long time after the change. They had to implement a lot of changes to help reduce that toxicity, and probably went back to considering the downvotes despite not showing the count.
You guys are forgetting about spam accounts, toxic individuals, trolls, etc. I think they need to take into account karma but just not show it.