Because that's an extra annoyance on both sides.

Extend this logic to other thing you should ask about, and you'll see it gets creepy very fast.

This. And also, the problem is people want to have too much control. You should build your society in such a way that if you lose control (a bit), its no problem. That is the real problem with tracking of parents and -for that matter- the security agencies. You should raise your children to be resilient. If they get lost, teach them how to get unlost. They should recognize danger by the stories we tell them and the experiences they had. Sometimes this goes wrong, and that is super sad, but things go wrong in life. There is no real way of preventing things to go wrong. We are now making sad human beings by putting our kids into a safe bubble.