I used to share your opinion about down votes, until I read in the HN guidelines that there was no explanation for what down votes really were for, while flagging was explicitly defined.
It seems the HN cultural practice is to down vote posts people don't like or just disagree with. I would rather people reply, but I can't do anything except for practice what I believe is right: I'll down vote a post that doesn't contribute to the discussion, as you do.
Since "doesn't contribute to the discussion" is vague and subjective, I can't claim particularly high moral ground.
It seems the HN cultural practice is to down vote posts people don't like or just disagree with. I would rather people reply, but I can't do anything except for practice what I believe is right: I'll down vote a post that doesn't contribute to the discussion, as you do.
Since "doesn't contribute to the discussion" is vague and subjective, I can't claim particularly high moral ground.