I would interpret it as a more general "nah". The author could then reflect and likely see reasons why someone would disagree.
Reasons for disagreement could be many. Doesn't seem right to shut them up and leave them to guess what the problem was.
I create throw-away accounts (one per device, until I clear cookies, and then a new one). I have one where literally everything I post gets a pile of downvotes. I'm assuming someone's stalking that one and using an army of bots to downvote everything I post, presumably because I offended them at some point.
I think the fix is for a downvote to require a rationale -- you need to state why you're downvoting. Poster learns what not to do. Downvoter needs to do it for a quasi-rational reason.
The internet has a small set of hyperactive people. It has a larger number of people (like me) who don't bother with karma. And a huge number of people who check out and don't participate in discussions. I don't think there's much alignment between the groups, and who you want posting.
The mods / downvoters / etc. are in the hyper-active group, and on most sites, overactive mods tend to lead to echo chambers, and to a lot of people checking out. I haven't left HN because of this (I think the karma minimum for downvoting helps a lot), but I've left many web sites when they became too dumb or too one-sided.
HN hasn't yet gone stupid, but there is a strong correlation between downvotes and political alignment. I'm not so much talking about just left/right, but also libertarian, tech elitist, etc. I think 90% of whether my posts end up +10 or -2 depends on how well they align.