KindViper
The rationality, as I suspect you might have begun to realise, is in rejecting this guidance as precisely that.
You are absolutely right that it is guidance – guidance on the law on equality, just as the Highway code, while not itself law, is guidance on the law regarding the road and driving. If people dislike it, they need to work to change the law; the guidance cannot do that, and has not done that. The equality law remains as it has been since 2010, and as it remained even when certain malign organisations declared that it was not the law and started lying about this to all and sundry. Just saying "the speed limit is not a legal requirement because the guidance says that it is" does not stop it from being a legal requirement.
Rejecting or ignoring the law because you don't like the guidance about it is likely to lead you to a court of law; that's what eventually happens when you break the law. You may drive at speeds over the speed limit, but you do so at your own risk; you may elect to discriminate against one protected characteristic (or two, or three, in this case: religion and disability must be taken into account as well as sex when treating gender reassignment preferentially) in favour of another, but you do so at your own risk.