It's not as if airplane mode can't be turned off. It just can't be turned off using a widget toggle switch. At first I was thinking maybe it was to prevent someone from turning on airplane mode to substitute their own calling service kind of hijacking your calls, but that doesn't really even make sense, and if the radios are off how would it connect anyways. You can still turn WiFi off and on through a toggle as well as Bluetooth. And I guess on some phones airplane mode turns off GPS, on others it does not.