> There was a reply here, now dead, that I wanted to discuss
If there's a comment that's [dead] that shouldn't be, you should vouch for it by clicking on its timestamp and then clicking 'vouch' at the top of its page. When enough users vouch for a comment, it is restored to visibility. That's why the comment you're talking about is now visible (https://news.ycombinator.com/item?id=20495142), albeit also downvoted.
Users have more power to do that than they think they do! It's really a feature for community moderation, and probably the single most salutary thing we've added to the site in the last five years.
If there's a comment that's [dead] that shouldn't be, you should vouch for it by clicking on its timestamp and then clicking 'vouch' at the top of its page. When enough users vouch for a comment, it is restored to visibility. That's why the comment you're talking about is now visible (https://news.ycombinator.com/item?id=20495142), albeit also downvoted.