The central idea is that being a woman, trans or not, isn’t a licence to ride roughshod over the needs of others; that it comes with rights, but not infinite ones.
That cuts both ways, obviously.
This isn't what the judge decided. He reckons he has settled 2 of the 4 points that were brought to this preliminary hearing.
The first was whether Maya's beliefs were protected under the EA - he said no because they failed Grainger 5 - i.e. that they amounted to harassment of those with the PC of gender reassignment (a PC which incidentally does not apply to Gregor Murray, Pips/Philip Bunce or Clair Quentin).
The second was whether genderist ideology was a protected belief under the EA and if so, whether Maya's disbelief was therefore also protected. He totally swerved this one.
Tayler decided it was not necessary to apply the Grainger criteria to genderist ideology because it was obviously correct. The analogy he used was a philosophical belief that murder is wrong, and the corresponding disbelief - 'I don't believe that murder is wrong.' He said there was no need to do the Grainger thing on the belief side and of course the disbelief side fails (paras 58 and 92).
He basically said TWAW just like murder is wrong.
Had he applied Grainger to the genderist ideology he would have had to admit that an absolutist belief that TWAW inevitably leads to harassment of women and girls on the grounds of the protected characteristic of sex.
Harassment in the EA is unwanted conduct related to a protected characteristic that violates someone's dignity or creates an intimidating, hostile, degrading, humiliating or offensive environment for them.
This is why we have the single sex exceptions - they are there to prevent harassment.
Preventing harassment is ALWAYS a legitimate aim because harassment is prohibited conduct.
Excluding a tw is ALWAYS proportionate because including only one tw makes it a mixed sex environment for everyone.