@Stompythedinosaur
Procreation requires a male and a female. Female brains are also generally smaller than males, as the female skull is smaller.
You seem confused.
Not confused at all. You are demonstrating my point beautifully.
Bigoted people find a (true) biological fact and fixate on it as if it justifies their discriminatory beliefs. So, women having a smaller brain size doesn't actually indicate lower IQ and certainly doesn't justify paying them less in the workplace. Procreation has require sperms and eggs, but that doesn't mean being gas is unnatural and wrong.
People cannot change their genetic make-up, but that doesn't mean their perception of their gender is incorrect, or that they are expressing it in order to attack other groups of women.
Ok, let's accept firstly there really is something innate that trans women have in common with all other women but not with any men, and secondly that this something is a more appropriate(*) indicator of womanhood than the observable physical differences we've been using up til now.
That doesn't change the fact that the rights and protections that exist for women today were put in place under the old definition.
So why does it follow that changing the definition of woman automatically means the rights and protections created for one group of people, the female, need to be opened up to a different group of people, the woman-identifying? Especially since the reason women (old definition) needed these things was entirely down to their biology and the way society treated people with that biology, challenges that by definition trans women do not or only partially share?
Since those rights and protections were created under a definition of woman that literally excluded trans women, why are we now assuming they will somehow work for trans women as well?
I think it's valid and not bigoted to say that if we as a society are going to accept that trans women as women, that question needs to be answered and perhaps some changes need to be made to existing structures before self id trans women can be included.
* I chose "appropriate" here after a lot of thought. Other words could have been "real", "useful", "meaningful", "effective" but I chose not to use them because I felt they were too tied to my own beliefs about the reasons we sometimes need to differentiate between men and women. However I think it's worth flagging that behind that weasel word "appropriate" is a whole other conversation about when and why we need to identify and separate men and women in the first place, and that is probably the conversation that needs to happen before we can agree exactly what criteria should be used to do it.