[All these points apply to sex and to gender, so for ease of reading, I'll just discuss gender]
Gender-exclusive groups are common in many societies, such as men-only and women-only social clubs and casual activity groups like a men's bowling group or a women's reading circle.
Sometimes this is de-facto, but sometimes this is enforced by rules or expectations, treating the club as a safe space for airing issues people have with other genders, or avoiding perceived problems with other genders.
I came across this old comment in a garbage subreddit by accident when researching. The topic is Men's Sheds:
"Here's the thing. No reasonable person has an issue with women having their own women's activity groups. The annoying part is that whenever men try to do something similar, that's a problem. Women either want them banished or demand entry, EVERY time."
I think their claim is nonsense, grossly exaggerated at best. I also know of many counterexamples of men trying to get into women-only groups (as an extreme case, the Ladies Lounge of the Mona art gallery in Australia was taken to court for sex discrimination, with the creator claiming they would circumvent the ruling by installing a toilet). But nonetheless, I can understand why they feel this way, patriarchal social relations change how most people see men-exclusive spaces vs. women-exclusive spaces.
But my response to their claim is that, I am reasonable and I do have an issue with any group setting up places which discriminate based on gender. These safe places can form as a legitimate rudimentary form of protection, yes, but they maintain and often even promote sexism, and should all be challenged and turned into something better which serves the same purpose.
Of course, I'm limited by my own experiences and perspective, so I'd love to hear your opinions on the topic.
Bonus video: "Why Do Conservative Shows All Look the Same? | Renegade Cut" - a discussion about fake man-caves and sexism.
"I'm open to the idea of women only spaces if they serve a function"
and those people know that.
so what exactly is the problem with women only safe spaces?
I’m speaking of my experience of being trans nonbinary and having been discriminated against under the guise of gender exclusive spaces. Cis women have a long history of excluding trans and nonbinary people from ‘women only’ spaces so excuse me for being sceptical of the concept.
that is most likely due to the fact that cishet women who experience long term abuse by amab persons (often their former partners) need amab free spaces.
again I encourage (and participate in) both women only and queer open spaces, but they both have their right to be.
The misuse of AGAB language to exclude trans women from women-only spaces is just transphobia dressed up in "woke" language. "Assigned At Birth" is a verb. It is something that happened to trans people coercively. It is very frustrating to see cis people weaponize this term that they don't understand to just do slightly different sounding transphobia. If a space is women only but excludes trans women, then it's just an admission that the group does not see trans women as "real" women. If a women only space wants to exclude all nonbinary people for whatever reason, that's fine, but this "AFAB-only" schtick is very transparent and it would be refreshing if those groups would just be honest about their transphobia instead of playing this silly language game that they pretend is still inclusive.