Maybe because it's critical of the AI and the whole SV culture. Maybe because of the f-bomb. Or maybe because it's a dupe of a dupe of a dupe: https://hn.algolia.com/?q=piledrive
It's not an exact dupe, but the main part of the content is too similar. You can send an email to dang so he can take a look and give an official opinion hn@ycombinator.com
The original, most discussed one is here (with censored headline) and is not flagged: https://news.ycombinator.com/item?id=40725329