This post was killed by user flags.
Forgive my ignorance, but what are user flags, and how are they used to kill a post? I did notice that this post dropped off the front page quite quickly.
Flags cause a story's rank to fall and, if there are enough of them, kill the story altogether. When flags kill a story, we sometimes unkill it so the existing discussion can continue. I did that here.
I'd guess that the flags on the current post are because the it is just a reprise of a story from earlier this week, so more or less a duplicate.
A caveat. Please don't flag stories merely because they are on some unusual topic. If a post is intellectually substantive, and not flamewar prone, but somehow obscure or out-of-the-way, it is welcome here. Here's an example: https://news.ycombinator.com/item?id=5979384. We definitely want such diversity on Hacker News. (I mention this in case anyone still has the misconception that HN is for technology and startups only.)