Now, hm, why would you put non-binary people in with women instead of with men? Maybe it's because the vast majority of them are female bodied female presenting individuals who don't take hormones?
This seems to happen a lot, women and "non-binary" getting lumped in together. And it seems that, to be sufficiently progressive, you have to allow "non-binaries" into women's only (safe) spaces.
I guess it was the natural next step along from "if they identify as a woman, then they belong in women's spaces". So the opinion is, apparently, that "if they don't identify as a man, they should be allowed".
Honestly though, I agree that most (at least, most that I encounter) are girls or women, and most of those don't bother to look or act androgynous in any way.
My guess is: they wanted to be trans, but were female, and didn't want to be a gross man, so settled on non-binary. And then realised that they had effectively kicked themselves out of women's spaces, or weren't allowed to complain about misogyny, or whatever. So pretty quickly they backpedalled, keeping that sweet sweet trans status, while still being allowed in women's spaces. And they experience misogyny due to being misgendered, so are still allowed to talk on women's issues. As another bonus, they didn't have to bother trying to not look like women.
I did a quick google for "non binary in women's spaces" and found basically the same article written four or five times by various "non-binary femmes" insisting that they were totally still allowed to be included along with women (but don't you dare call them female).
A lady said:
It’s not as though I don’t like women, or being around them. It’s just that I am not one of them; I identify as non-binary. My presentation is very feminine — I wear lots of makeup, have a lob cut, and don’t bind — so I understand why most people don’t even think to ask about my preferred pronouns.
No transition necessary!
So if you're a bloke and you want to get into women's-only spaces, you may not even need to bother any more with calling yourself Shirley and throwing on a skirt. Just say that you're non-binary (they/them) and talk about how you want a safe space away from the icky men, and how dare they bring up your full beard and muscle vest as though it's some kind of barrier.