I think I'll stick up for us a little bit here. I said "my current sense" because I like to be cautious. But I literally look at every single negatively scored comment on the site—a task akin to walking through slop—watching for cases where the downvoted comment was both substantive and civil. There aren't many of them, in my view. 1% is an overestimate. If you think I'm wrong, let's see some examples. They ought to be easy to find.

Lame comments that aren't rude but just mediocre are also a problem, and one which has been growing for years. That's not really what Sam's post was about, though. We can't solve every problem at once; we don't even know yet what will help with that one. One thing that would not have helped, though, is allowing toxic comments to run rampant. HN already lost some good users because it was heading that way, and we weren't about to let that keep happening.

Edit: By the way, since kogir and I made this scoring change, noticeably fewer accounts have been getting banned.