You could say anyone ‘opted in’ a Muslim could decide to be a Muslim, does that mean it’s ok to criticise their choices?
That is because being a muslim is a question of faith, not physical state.
You are not the suffragettes take 2, you are scared of what you don’t understand and creating an enemy because you can’t see or feel gender dysphoria yourself.
No, I just want to be able to define women.
I’ve asked the question and most people wouldn’t be happy with a transsexual with full surgery using their spaces either because ‘what is a woman’.
In most situations they wouldn't have any choice because in day to day life there is little sex segregation and usually the extent of sex segregation is up to the service provider. People might not like me bringing my 6 year old child into the opposite changing rooms at swimming, but there is little that they can do about it.
Under the current law there are only a very few situations where somebody with a GRC wouldn't be treated as having their acquired legal sex.
However, as you say, Self ID could lead to the situation being abused.
Earlywalker you seem to be doing what you accuse MNers of doing - seeking out a position you disagree with on the internet.
I wouldn't be concerned if the people asserting that sex doesn't exist were only randoms on the internet, but unfortunately they aren't.