As a 53 year old who has been interested in technology for my entire life I'd say that in the past the technology industry has never been anywhere near as outwardly political as it is now.
When the front row of the presidential inauguration is every major tech CEO, well yeah politics are going to to come up in technical spaces.
tl;dr - The shift you are seeing isn't specific to HN.
I don't entirely agree with the FSF on everything but my first internet email address.back in -1992 was gfm@gnu.ai.mit.edu
I'd argue that the problem isn't necessarily an occasional political discussion, but that all political discussion here feels like somebody copy and pasted a few longer-ish social media comments into an HN comment tree. It's as if the moment politics is mentioned, people magically forget where they're discussing it, and before long you end up with a flood of childish insults, flaming and nonsensical accusations of conspiracy.