I agree with you that the HN political slant I see defies single labels. On the one hand, there is a significant civil-liberty lean (personal privacy and gun rights, for example) which is not generally associated with (US) "progressivism".
On the other hand, automatic disdain for the hegemony is a pretty progressive lean.
This is why summarily labeling folks as "nazis", "racists", "genocide supporters", etc. doesn't advance the conversation; it shuts it down, and my feeling is that's why we're seeing the types of political threads we see on HN (that are dominated by like-minded individuals ranting against whatever cause they happen to espouse).
IMO, this siloing is not a sign of a healthy community. My preference would be to get back to more technical discussions and try to avoid discussion of politics insofar as that's possible.
But I don't speak for anyone else and can only control how I engage in discussion here. I choose to disengage in political threads. That other (non-HN-mainstream) voices do as well is probably one of the reasons why the self-reinforcing echo chambers exist in the first place.
That's my objection to political discussions on HN.