Earlier quoted context omitted.
Why has this been posted here? Because it relates to the public doings of YC, which are always on-topic (overriding the "no politics per se" rule).
Indeed? The logic of your well-thought out and ponderous argument is utterly overwhelming. Might have as well said "Because we can!"
Actually it's a pretty straightforward consequence of the HN guidelines, which clearly do not forbid all political discussion; just "politics for its own sake", i.e. political talk not strongly anchored in some other intrinsically legitimate topic.