And here's a compilation of all the comments so far that are the misogyny equivalent of "So when is it White History Month? And why don't White Lives Matter?"
Also lost count of the comments of "but what about Trans Women??" and "But How can you possibly define what a woman is? It is impossible!!!"
(In case anyone on this thread thinks the comments in this image are reasonable : all-female gatherings, facilities and opportunities are permitted because it is legitimate for women who are disadvantaged compared to men in many ways, to organise to combat those disadvantages and to create a springboard to enable women to participate on equal terms. All-male gatherings and opportunities would be intrinsically working to advantage the already-advantaged and priviledged and no that is not legitimate. The all-male clubs where deals are done and power is brokered are not in any way equivalent or legitimate. All-male facilities for changing, washing etc with privacy and dignity without a bunch of women giggling about the size of your cock is entirely legitimate though. For exactly the same reasons it is legitimate to have gatherings and opportunities that exclude white people, but it is not legitimate to have gatherings and opportunities that exclude non-white people. People have forgotten how to check their privilege. The disadvantages and challenges that are intrinsic to being female do not apply to transwomen (as they are male) although some of them do apply to transmen (as they are female). It is entirely reasonable and legal for groups like this to be emphatically Single Sex.)