I'd suspect the feeling is it's never too young now that incidents like Sandy Hook School are behind us.Simple suggestion - remove the numeric keypad & restrict inbound callers. Problem solved.
Parents really want something like this:
From a parent's perspective, most small kids don't need a full fledged phone. They need the functional equivalent of a StarTrek communicator
. They need to be able to communicate with "The Bridge" of "StarFleet" for instructions; to ask or get permission; to request a beam-up; or (worst case) to scream for help.
If the mobile market were smart, for little kids, they'd create a simple "phone home" model that only had three buttons: (1) call home, (2) call mom/dad's mobile; (3) call 911. And this same phone would require either a PIN entry or a number previously stored on the phone to connect an inbound
caller. That way only people authorized to call the kid would be able to do so.
Older kids would get a scrollable directory of numbers they were allowed to call instead of a few simple buttons. Inbound restriction to authorized numbere and PIN callers would still apply.
Do This and the average parent would likely get a phone (and pay for an account) for everybody in the household - including their newborn and the family dog.