What I don't understand is why it apparently doesn't occur to the HN admins that "fading" peoples' posts into oblivion makes people pay more attention to them. If HN's intent is to make undesirable opinions less visible, it's a colossal failure.

Often it's a waste of time to highlight those posts with my mouse, because they're usually downmodded for good reasons. But I still feel compelled to look, and I doubt I'm alone in that respect.

To fix this, I'd limit the text contrast to two levels -- normal and obviously-but-not-illegibly faded. In other words, don't make it look like you're trying to hide something from me. If a post is so bad that it deserves to be rendered at near-zero contrast, then it's bad enough to delete altogether... and only blatant spam falls into that category IMO.

For me, I think it actually works well as a user interface.

If I'm in a mood to be charitable and particularly open-minded, I can choose to squint closely or highlight with mouse, and read a greyed-out comment.

However, once that reading is done, the fact that it's greyed out means I don't feel the need to respond to it, correct it, etc. I know that it's being hidden, that people will give it less credence and attention. Plus, I just don't have to look at it once it's no longer highlighted.

In effect, greying out text is a gentle reminder to "don't feed the trolls"

Or just click on the timestamp to go to the comment's own page, and then the fading should be turned off.