"unless woman and man are based on the fixed points of two biological sexes, the law is an incomprehensible mess for everyone. Hence the decision taken."
That was the point I was making. Seen from here the law is an incomprehensible mess and the judgement of the SC adds another to what already exists.
It will suit some to say that the judgement is good and others that it's bad. Many will feel it has little relevance to their lives and an unfortunate few that their lives will be harder still now.
To borrow from Andersen's tale, the emperor still has no clothes but that's no laughing matter and it clearly isn't academic because there is and will be fallout from this judgement. Many have strong opinions which may be justified by appeal to this authority or that, which might not be useful in debate.
You can't easily legislate and find common consent in an area which is anything but clear just now. Genetics, genomics and now epigenetics are rapidly developing fields in biology. Science is ahead of social change and there are no certainties in it, to the discomfiture of many. Imagine a world in which we could change our sex at will. It may yet happen.
Neither sex nor gender are the most important things about us, perhaps?
In the creation story, my sympathies mostly go to the serpent.