I haven't been flagging these topics, but I have defended those who do, on the grounds of "not politics" and "leads to flamewar discussions". On the politics front, you have deliberately allowed more politics recently (or at least that's my perception) when you thought it was of general interest, or of tech interest. But the discussions are, perhaps less flame-full than expected, still somewhat incindiary (not least the discussions around flagging, with accusations up to being full-on fascists aimed at those who just don't want HN to be overrun by this).
So: What made it clear to you that this was something that should not be flagged?