I know some people DV due to 'disagreement with rewards' and that can be a tricky one to argue unless it seems that people have conspired to vote up a low effort/value post. There is no agreement on what any post is worth, but that is what votes are supposed to decide. Accounts like rancho throw a spanner in the works. We don't know what his criteria are.

Some people won't comment when they downvote, but then they are not forced to.

I get that it can feel like a gut punch when you get a big downvote, but it's part of the wild west of Hive.