Just some background: there is a controversy in the Ruby community[0][2] around the governance of the rubygems project. It has been maintained for a long time by employees of Ruby Central but not in a corporate capacity. There was a recent hostile takeover of this project by the Ruby Central corporate arm.
The most likely reason it was flagged from my perspective is that David Heinemeier Hansson (who created rails) is kind of the figurehead of this community and he has controversial opinions[1] which people believe make him unfit to represent their community. The controversy has manifested as people speaking out against DHH in his position. So this post seems to have been flagged for being "political" because it is seemingly in opposition to rubygems for the DHH reason.
0: https://hn.algolia.com/?dateRange=pastMonth&page=0&prefix=fa...
1: https://davidcel.is/articles/rails-needs-new-governance (this article has a lot of examples from DHH's blog)