"I believe this story or comment contributes to the community good in some way, and I would like to see more like this." I think comment downvotes are supposed

"I believe this story or comment contributes to the community good in some way, and I would like to see more like this." I think comment downvotes are supposed to be the opposite of the above, but in practice it seems to be used to say "I don't agree with you," or "you don't know what you're talking about." Mere agreement or disagreement should probably be handled with a comment, to further the conversation. You could easily disagree with a comment, but upvote it, if you thought it contributed something worthwhile. There are Guidelines and a FAQ at the bottom of most pages.