what I was objecting to is the idea that women's organisations must always either include or exclude trans women.
Sorry, but you need to be clear in what you type. I know you think any old words can be substituted for others, but if you do that you can't communicate.
As you refuse to let anyone know (that pesky communication again!) what it is you mean by the word 'women', I'm going to assume you mean 'all adults'. So, again, an organisation for 'all adults' (what you think of as 'women') would include trans women.
If you mean something else that isn't 'all adults' you will need to make that clear so I can understand what you mean by 'women's organisations'.
If you mean 'organisations for piano-players' then there would be no discrimination on sex.
If you mean 'organisations for left-handed people' then there would be no discrimination on sex.
If you mean 'organisations for people experiencing disability' then there might be discrimination on disability.
The only way there would be discrimination by sex is if sex was an eligibility criterion.
You don't think that sex is related to whether someone is a woman, so what do YOU mean by 'woman's organisations'? What eligibility criteria are YOU talking about in these orgs if it isn't sex?