Of course you can't teach an old dog new tricks, but describing everybody who posts low-quality comments as "selfish, uncaring people" is pretty extreme (and not a little unkind in itself). I think many of them are simply new to HN and not yet aware of the way things are done around here. And for these newbies, posts like the one above are exactly what we need.
One thing I like about HN is that it is very self-observant. Although I sometimes tire of the repetitive posts on what constitutes a bad comment, or what downvoting should be used for, it is precisely these constant discussions that ensure that every regular HNer knows what is expected of him/her.
Finally, I think we're already pretty good at handling negative comments. So far, the combination of flagging, downvoting and commenting has worked pretty well - even if it isn't completely perfect. I still have hope for the future :-)