HN intentionally flags and removes controversial comments and posts, with the intention to prevent trolling, flame wars, and other detrimental behavior patterns. This is considered a feature, not a bug [0].
This ensures that HN provides a semi-curated discussion weighted towards technical and scientific issues, and against geopolitical or socioeconomic topics, for example.
That isn't a statement that these topics shouldn't be discussed, just that they aren't necessarily appropriate for discussion here.
[0]: https://news.ycombinator.com/newsguidelines.html