[jodrellblank]

Common retort: don’t just downvote me, tell me why I’m wrong.

"Please don't comment about the voting on comments. It never does any good, and it makes boring reading." - https://news.ycombinator.com/newsguidelines.html

[hobofan]

I _think_ this rule is intended to discourage "Have an upvote" (and similar) comments, commonly seen on Reddit.

Reminding fellow readers/commenters to not just shallowly dismiss comments once in a while doesn't do much harm, and actually lead me to reply to the parent.