I agree, but even though fair, I just wonder whether the open category could ever be meaningful. The amount of investment to run a while separate category, but who would be competing in it? There are examples of transwomen and transmen continuing to compete in their sexed categories, so it would surely only be a minority who would enter "open".
Anyway, from what PP says it may be that an open category was rejected? I should maybe should read the source material!