Users have fedback that people focus more on downvotes to disagree rather than participating in the conversation, this is exacerbated by the fact that guest accounts can also upvote/downvote.
Possible solutions:
1) don’t allow guest accounts to upvote/downvote;
2) remove downvotes and only allow people to upvote;
3) replace upvote/downvote with contextual references, possibly icons or text descriptions like “funny”, “helpful”, “informative” or the like.