It is flagged because enough users clicked on the "flag" link/action. Users tend to do that for stories they don't feel belong here, which especially happens with politically loaded non-tech stories, as they are listed as off-topic in the guidelines[1]:

Off-Topic: Most stories about politics, or crime, or sports, or celebrities, unless they're evidence of some interesting new phenomenon. If they'd cover it on TV news, it's probably off-topic.

Moderators sometimes unflag stories, if they feel the discussion is genuine.

[1]: https://news.ycombinator.com/newsguidelines.html

25c army

> Why is this flagged?

The people have voted.