[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 curious whether you think you think this applies to, for example, a spa or locker room where people are in various states of undress and are separated into exclusive spaces based on gender?
I would hope that in 25-50 years from now, gendered locker rooms and bathrooms will be a thing of the past, and slowly replaced with individual unisex stalls. Maybe for high volume places (like a stadium or airport) there will still be bathrooms with a wall of urinals, but those will probably not be labeled "men's" and will just be urinals.
The public pool locker room is the last place in american society where you can exist legitimately naked in public.
Moving to a place where everyone is expected to go into a private stall seems :(
I live in Denmark and that's at least how bathrooms are basically everywhere here. It's nice.
That's a good question. In fact, I think just yesterday on reddit the front page had a photo of a sign at a public bath in China saying something along the lines of "No homosexual men allowed", with top comments hypothesizing it was probably more about banning unwanted or public sex acts than homophobia itself.
I assert that this kind of gender segregation is usually about deterring sexualization (and even sexual violence). This is the case for spas, locker rooms, toilets, or even more general places like gyms. My basic position is that being able to deter unwanted sexualization is a useful goal for many reasons, but that's a rudimentary attempt to solve it. At best, I'd say it's a coping mechanism which should be understood as such. So I don't believe they must immediately be abolished, that might be utopian, we need to begin mainstreaming a culture that would enable these sexist institutions to be abolished.
But ultimately:
I think people often don't seem to realize that sex-segregated bathrooms were a relatively recent invention, going back only a few hundred years: https://time.com/4337761/history-sex-segregated-bathrooms/
I do think the assumption that women will be attacked or sexually assaulted underlies at least some motivation (the TIME article above claims it is a view of women as weak and the public as dangerous - which generally fits that view). The fact that this reasoning was used to justify segregation in every aspect of public life, to the point of having separate train cars, and yet we saw that segregation go away nearly everywhere but bathrooms, it makes it seem like the claims about safety could have been overblown (or maybe more accurately: that segregation doesn't necessarily protect as much as it claims). The TIME article argues that the only reason bathrooms are still segregated has more to do with the difficulty with changing codes and standards than anything like actual safety reasons.
OK, here's another question: in the Middle East / Western Asia misogyny is quite a significant problem (that might be an understatement), and in northern Syria there was a women-only militia formed called the YPJ. The YPJ was formed as a group based on egalitarian, feminist ideology and has been praised for having improved the power and situation of women in that region.
It seems to me that segregation is sometimes used to oppress women, but sometimes segregation is also how women are able to carve out independence and push back against their oppression.
What do you make of this example of women who under extreme oppression were able to form a women-only militia which then increased the power of women in the region?
Link to that reddit post
Those are different things, and I think it important to say that because your question reads like you're conflating them, when you aren't; you're asking how far it does stretch, not saying that locker rooms are the same as a social club.
Which isn't directed at you, but any passersby that didn't catch it
As far as that goes, I'm actually okay with shared lockers/showers/bathrooms, so long as you can find privacy as an individual. Stalls with good isolation for them what care in other words. I don't, however, think it would be okay to enforce that at this point in time
sorry by spa I was implying not a social club but a place like baths or an onsen where women might be naked in baths together; typically these spaces are sex / gender separated
I think the assumption in my question is that in the baths and locker rooms we assume the spaces are open and people do not have total privacy when in states of undress.