I use the userscript I have linked in my profile to disable the fade for downvoted comments but there's only so much you can do.
And to be fair... there are some subjects for which Hacker News has proven less than capable of maintaining civil discourse, and some subjects like mainstream news and politics which are legitimately off topic. But it would be nice if people learned to just ignore sentiments they both disagreed with and were neither willing or capable of a reply to, and just hid threads they didn't want to participate in.
edit: fun note, we joined HN basically at the same time
Something much more common and harmful to the quality of discussion is dumb stuff getting upvoted. Oddly, you never see anyone meta-fuss about that.