Earlier quoted context omitted.
The purpose of flagging is to indicate that a story does not belong on HN. Frivolous flagging—e.g. flagging a story that's clearly on-topic by the site guidelines just because one personally dislikes it—eventually gets an account's flagging privileges taken away. https://news.ycombinator.com/item?id=12173836
GP is arguing that it does not belong on HN.
0. HN links only have to be interesting, to belong. They don't have to be tech-related, despite this being a widely-held belief.