It's not that easy. Bad compliance will lead to an early death in diabetics. And kids are VERY bad at compliance. Most parents who can afford it nowadays get an insulin pump for their kids. And they are so ridiculously complicated to operate, and one single lapse can be dangerous. You're always doing math in the back your head, considering what you've eaten (or will eat), whether you will do sports, etc.. A custom firmware with auto-dosing can be a real life changer, and saver.
Source: A friend of mine is part of a insulin pump hacking community
Source: A friend of mine is part of a insulin pump hacking community