Not being good at a sport is not a “de facto ban” it is just not being good at a sport.
You are absolutely right. I was thinking of men/boys who had undergone hormone treatment, which would render them completely uncompetitive with regular male athletes. But they still shouldn't be allowed to compete against women or girls, as they still enjoy a substantial unfair advantage. Plus it was their choice to undergo hormones, and they should have to bear the consequences.
I had assumed these boys in the court case had started hormones. But on reading other articles, I see they have not had any medical transition treatments. Just completely self-id'ed as girls. It would still be unfair even if they were on hormones, but this is doubly ridiculous.
The quote from one of these boys that "It is both unfair and painful that my victories have to be attacked and my hard work ignored.” just shows have arrogant and narcissistic many of these people are.