That's an inaccurate perception. HN has had a high number of political threads on the front page in recent months, and most (nearly all, in fact) have been critical of the current administration.
If you find that hard to believe, see these lists:
https://news.ycombinator.com/item?id=43227619
https://news.ycombinator.com/item?id=43168527
They are a couple months old now, but the point hasn't changed: the most-discussed (by far!) topic on Hacker News gets perceived as totally-suppressed-and-silenced by the passionate portion [1] of the audience that wants more of this material. I call this the "nobody goes there anymore, it's too crowded" theory of HN threads. [2]
This is not a new phenomenon [3]. Here's an example of the same thing from 5 years ago: https://news.ycombinator.com/item?id=23624962. That was me responding to someone complaining that the most-discussed-by-far topic on HN was being "aggressively removed from discussion".
Meanwhile, the audience that wants less of this material perceives the site as being completely-overrun-by-politics. To these we have to give the inverse of the current explanation. You can see from https://news.ycombinator.com/item?id=17014869 how far back that goes.
Both of these perceptions are wrong. Both are consequences of the fundamentals I listed in the GP comment. And both are special cases of a more general phenomenon: for anyone passionate about topic X, the HN front page never contains enough X.
The most passionate users rarely express their preference as "I would prefer more X on HN". Rather they say: "It's unbelievable how X is completely and utterly suppressed and censored on HN".
[1] https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que... I use 'passionate' or 'passion' a lot to describe these segments of the audience (on any topic and/or side). This is not intended disrespectfully. People have legitimate reasons for feeling passionately, and often the topics are far more important than most stories on HN. However, mitigating the power of these passions to shape HN is critical to keeping this the kind of site that it's supposed to be. If we didn't do this, HN would turn into a current affairs site overnight.
[2] https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...
[3] The reason this is not a new phenomenon is because of what I said in my GP comment: it follows from the fundamentals of the site.
p.s. The thread you linked to spent 15 hours on HN's front page. That's a lot.