Um, it costs money (both a fairly hefty (for a kid) price up front, and recurring). And at the rate most kids text, it would cost a lot of money on a prepaid pl

Um, it costs money (both a fairly hefty (for a kid) price up front, and recurring). And at the rate most kids text, it would cost a lot of money on a prepaid plan. And then if they want to use a phone in their parents' presence, they need to be using the iPhone. And the parents might wonder why the kids almost never answer their calls (to the iPhone).