Same goes for virtually any space that used to be male-only. It's become socially unacceptable (and often illegal) to exclude females from anything, while it's still perfectly OK to exclude males.

What’s an example of a male-excluding space you’ve seen that couldn’t have a female-excluding counterpart?

1. Women-only workout areas in gyms - quite common, never seen one for men

2. All-female colleges (many), there is perhaps one or two all-male, if they even still exist

Just google something like "women business network".

Also the "WIN" network.

Boy Scouts

That's mostly it being a victim of its own success; here in Canada, Scouts long held a better reputation than Guides. Something fundamentally different about how the organizations and parental leadership approached the kids, I suspect.

Scouts are not integrated. Troops are separated by sex. They are safe in their spaces.

That second sentence breaks the HN guidelines badly. Would you please stop doing that and follow them instead? I don't want to have to ban you.

https://news.ycombinator.com/newsguidelines.html