I agree with you that parents absolutely have a responsibility to watch their children. To use your example, if young kids were running around the parks unsupervised putting themselves and others in danger then yes, I would expect Disney to step in and do something to enforce that this is unsafe and stop it from continuing to be a problem. Whose responsibility is it that kids wear masks? Their parents'. But when parents fail to put a mask on a child or fail to make the child wear it properly, a cast member steps in and gives a reminder. We can all agree that inappropriate, unsupervised pool behavior shouldn't be happening because parents should nip it in the bud, but they haven't and it is. So what now? IMO time to make changes to a policy that in theory is absolutely correct but in practice is not working. Time to get a lifeguard in the splash area or at least passing by from time to time. Or maybe even someone just watching to see that all children enter with an adult.