Asklemmy

Stallman is seriously flawed as a leader and a spokesperson. In 2018, for example, he insisted on including a joke referring to the "global gag rule" in the documentation for abort() in glibc

The joke despite not being technically essential it is what gives software the sign that its created with love and its cherished by its creators and users alike, leaving easter eggs is not a flaw of the software.

I've read reports that he has contributed to an unwelcoming environment particularly for women, both off and online, and I have no reason to doubt those reports

Most likely you read these reports during the "open letter" targeting RMS. I believe these were being hyperbolic towards the actions of RMS since a lot of companies would benefit from RMS stepping down from his position and thus were creating (not necessarily) fake (anonymous) scenarios to devalue RMS and many (if not all) were debunked or proved fake.

More generally, a fundamental flaw of Stallman's in my opinion is that he often seems to form opinions on matters that do not concern him

They're opinions for a reason and have nothing to do with Open Source or the GNU and he states that in his website stallman.org

relevant communities, often running counter to the widely accepted opinion in those communities

Good point, they're still opinions and have no real value except as ideas

Most controversial is his article against singular they/them (which, to my knowledge, runs counter not only to consensus in the trans and non-binary communities but also to generally accepted linguistic practice overall)

I agree with Stallman on this one, but i dislike per/pers specifically, if a better alternative was decided upon on itd be great

he shows this tendency elsewhere for example when he argues that "piracy" is a smear term (which was technically true at some point - but this term has long since been "reclaimed" (for lack of a better word) by the data sharing community, a fact he does not even seem to mention)

I strongly disagree with this point as, although it is used by a lot of people, it will always imply that youre doing something inheritely illegal and unethical when it should be a human right to share your possesions with your neighbor at will

His anti-glossary is full of more examples.

I agree with over 90% of those examples, there's words that are pushed to fill in a narrative to create legal or political bias.