My model is that the section of the populace that is problematic for public health services is the one that looks for an excuse not to exercise and/or diet.
Skinnyfat people already have one a 20-25 BMI. You can be a physical wreck that can barely manage two flights of stairs, but the BMI says you're dandy. So take the lift.
Overweight people get one since it's well known how little muscle you need to sneak into that category so a wee bit of belly can be denied away unless you've got arms like a Tour de France yellow.
By the time you get to the BMI 30's and above, you're going to need industrial levels of denial to pretend it's lean enough unless you are a heavy trainer, by which number we've reached the point of BMI being irrelevant.
And it just feels wrong. You've got two largely independent variables - muscle mass at 43% and fat at 15% for males, and you're using their sum to diagnose excessive amounts of the smaller one.