Once you make one unscientific concession to bigotry, you'll make another. The problem with your strategy is that the opposition to trans athletes isn't actually a good-faith attempt at securing fairness in sports. This isn't some fair debate that reasonable minds can come together and hash out. If you surrender on this issue, the bigots just move on to the next one. And since you've already conceded to bigotry once, you've established the precedent that it is fine to pass laws based on pure unscientific bigotry. It starts with sports, but it doesn't end there. Now people's passports are being revoked because a bunch of cowards thought, "oh, it's just sports, that's not worth fighting over." If you give these fuckers an inch, they'll take a mile.