Like a child-proof cap that adults can't get open but kids can
So the iSIM is designed for neophytes in the 50-115 year bracket that have difficult times opening their pill bottles, with VCR's still flashing 00:00 and can't read the fine print on the pill bottles.
Meanwhile every kid I've ever known can probably find the virtual needle in the internet haystack, and are fairly knowledgeable in circumventing copy protections, jailbreaking iPhoneys and iMaxiPads, etc.
So how is this supposed to teach our kids about trust? If we're willing to violate their rights to associate and communicate with anyone they wish, then we've already lost the battle.
And I don't know about you, but I've had no problems obtaining second and third SIM cards - I never even had to ask. I'm sure kids are smart enough to rip off the stupid iSIM cover, or impersonate their mom and dad when calling the wireless company.
If you want to piss your kids off - don't give them a friggin' cellphone. If you're going to be a looser and the least popular parent on the planet, at least do it right.