It isn’t hate to speak the truth > J.K. Rowling
Good luck with that > Socrates
The distinctions that exist between sex and gender, nature and nurture — and perhaps most relevantly in this instance, between fact and ideology — are reassuringly non-absolute.
Yet the acknowledgment that a degree of blurriness exists does not invalidate the distinction in itself.
It is depressing to see stars of the Potter franchise falling over themselves to distance themselves from the author, in effect trumpeting their ideological purity — in much the same way that Pasternak’s peers in the writers’ union did for him in the USSR — especially as J.K. Rowling’s tweet appears to me to have been at least partly intended in jest.
At Girton there were no single sex washing facilities. This did not apparently cause any problems, but Girton is not the big wide world.
The College's very existence is testament to the historical issues faced by ‘people who menstruate’, who have tended to struggle in that big wide world, where they are a majority, to enjoy basic rights and protections.
Women who have never menstruated, a small minority in comparison, are also deserving of respect, rights and protections, but we cannot allow a cultural obsession with this inherently more niche issue to damage the situation of the people who menstruate in any meaningful way.
This is surely what J.K. Rowling has been trying to say.