What I can see is a fairly clear indication that they do not want contributions from people whose politics differ from theirs. I would also question whether government funding of a project with political policies about who can participate is appropriate. The political stance is also rooted in a particular culture so is unwelcoming to people from other cultures.
Of course people can political views and preferences, but they presumably have some aim in mind when making that statement in the README. What is that aim?
This is the same FSF that in the past has refused contributions from people whose politics include "I would like this software to run on my windows/apple/other proprietary platform". They're extremely political.
"If the point is to promote Free Software, we do ourselves a disservice by making our Free Software work better on a proprietary system than a Free system. Let's include this support when it works on the Free platforms as well."
FSF is political, but only about Free Software. Their goal is to promote it, and I think RMS has shown very clear thinking in this regard. I don't love the decision/outcome (someone did work to make something better and it was rejected), but I get it in service of the larger goal.
To flip the pschology, you could imagine a world where Emacs did way more awesome stuff on Windows and Mac, and the ensuing HN discussion where the obvious snipe appears a dozen times: "lol they keep talking about free software but their own products work better on windows lol".
They won't take contributions not aligned with their goals but won't block you from sharing your contributions in the spirit of free software.
Because you can have preferences while not restricting legal rights.
The GPL variants are the antithesis of politically neutral.
The GPL "tolerates" conflicting political opinions, which used to be closer to the norm and thus not political.
Other than that, there is no expectation of political stance.
Only in the current ultra-modern age, has politically neutral devolved to meaning that you must agree with me on 99.99%.
Of course people can have their preferences, but presumably that reaction implies "gay/trans anti-colonialist" ought to be a problem for some "political/cultural" groups?
What is the aim of that?
My read is that the authors are signalling their community is a "safe space". I don't think they're trying to exclude particular cultures, trigger people, or otherwise cause problems.