[biot]

This was discussed before [0] and I'll reproduce a comment of mine. TL;DR: downvoting promotes social standards thus it's neither antisocial nor pointless:

If nobody downvoted, then the author of the comment would be unable to distinguish between "the community doesn't value my comment" and "my comment was ignored". A downvote sends a clear signal vs. a lack of signal which is important to establishing/maintaining community norms. If we didn't have that signal, there might be reddit-style pun chains on HN and new users who see that might think it's accepted by the community since those threads are indistinguishable from other comments due to the scores being hidden. Seeing comments downvoted to grey is an important signal.

Of course, replying is also a signal but it's not appropriate in every circumstance. It's redundant when sibling comments provide correct information vs. the downvoted comment's incorrect information and an in-context reading of the thread will make that apparent. Or when the downvoted comment is flamebait/trolling and you don't want feed the trolls. Or when the comment clearly doesn't fit the community norms. And, most importantly, I have neither the time nor the inclination to reply to every comment on HN offering constructive feedback so I pick and choose carefully when I do that... as I'm doing here.

Long story short, HN deemed it acceptable to allow users with a minimum karma level to downvote. It's a feature, not a bug, and as long as it's used with discretion it sends a valuable signal to the comment's author. That feedback mechanism also confers positive benefits to the entire community.

[0] https://news.ycombinator.com/item?id=12070314