The situation can't be completely clear cut
Well put.
The key reason being that self ID changes the situation.
Up until now there has been a polite system in place for decades that everyone was discreet and fine about it and those who had dysphoria and transitioned to the point of looking the opposite sex just quietly used the opposite sex provision. No problems. Particularly since the massive majority of transsexual people using women's facilities were in orientation gay male.
Then came transgenderism ideology and self ID which put forward the idea that no visible transition was necessary and some women have beards and penises, no gender dysphoria was necessary, that men who are autogynephilic and who enjoy cross dressing, and who make up much greater numbers than the transsexual population with GRCs and are straight men in orientation, were as valid to use women's facilities as a transsexual person with full reassignment surgery, and that men were women if they said they were. And women needed to know their place, and get on with enabling this. And self ID should be any bloke who feels like it walking into any woman's space unchallenged, since by the act of walking in he has self declared his choice of identity and it is unacceptable to expect him to go through any gatekeeping procedures.
At that point, many women stopped willing to be polite and to do this on a good will basis. People like Miranda Yardley who have been part of that transsexual population for years, have been pointing out from the start that genuinely dysphoric and transsexual people are going to suffer if women are forced to draw hard lines about who and who cannot be in their spaces.