There may not be any evidence that this policy is beneficial for the kids, but the accompanying sense of smug self-satisfaction is probably very enjoyable for the parents.
If it helps we can argue that it breaks the "Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize" guideline.
My wife and I agree on these things and think it best for our child. Our relatives and cousins look at us like we are from another planet LOL!