Earlier quoted context omitted.
That's an anti theft feature. Intended to make the phone useless to a thief. It doesn't work very well, thieves manage to get around it somehow (not so much with Apple's version) so it ends up annoying the users more than it does deter thieves. Apple is really really difficult about getting these unlocked. The carriers can't do it, you have to show them proof of purchase and have an enterprise support contract. With…
It is a very good thing that Apple is tough about it, given the high value of the devices, and how people carry them around in public. I very much want my devices to be useless to thieves.
The IMEI is burned into the phone. They should definitely make it hard to change the IMEI; but they do. If the phone is stolen then the IMEI gets reported as stolen and anyone who tries to activate the phone with a wireless carrier gets caught.
Why does Apple or Google need to inconvenience people who forget their passwords or encounter the conglomerate's bugs?