the problem is that currently they have to have a diagnosis of dysphoria, and then "live as a woman for 2 years". Now some people may say that's a long time and they shouldn't have to wait. But as it stands, there are some checks and balances, not least for the transitioning person, in case the diagnosis was flawed or they change their minds.
If they can now just say "I'm a woman" and then get a GRC after 3 months "living as a woman" (which amounts to changing your name, possibly, using female pronouns and changing your driving licence - pretty much what the previous GRC requirements were, but without the 2 years and without the need for a dysphoria diagnosis) - where are the checks going to come? How do we know that they are a trans woman and not a twat with a grudge, or worse, against women? If we aren't even allowed to ask - a person transitioning has, in effect, all the rights of someone with a GRC from day one - how can we know?
If there is no harm meant, why is a 3rd space so abhorrent? This would show some lovely female solidarity with women who, for whatever reason but including culture and religion, cannot be where men are. And we know how that ends for those women: their world shrinks to their own 4 walls. That's not solidarity with women, is it?
For me? i have no issues with sharing a toilet, i have issues around places like a gym changing room/shower area where I'd be naked with male bodies. And i am the very anthesis of a shrinking violet: I am likely to say "this is for ladies". We do know how that can end too, though.
I also don't get the horror at having to wait 2 years from men in their 60s who suddenly say "but I'm a woman, i've been waiting years for this". Well, 2 more years, while you carry on living as a woman, isn't much in the grand scheme of things?
So i would really like to know: why the hurry? (some) Women in the UK got the vote just over 100 years ago. But how long was it before they could get a mortgage without a man countersigning? And sure we pushed, but we didn't steamroller and we didn't take away anyone else's safe spaces.