Tildes.net tries something interesting here: there is no downvote, but users can flag comments with one of the provided negative attributes (offtopic, noise, malice)[0]. This
discourages "downvote to disagree", and provides enough signal to e.g., sink an off-topic comment, but summon a moderator for malicious comments.
[0] https://docs.tildes.net/instructions/commenting-on-tildes#la...