The answer lies in what the beacon is for. It is there to warn others that the aircraft may now be unsafe or dangerous to those in the immediate vacinity. That will might be because things will move, the engines will start or the whole aircraft is just about to move off. Therefore, it is the people inside who say what happens to the beacon, for the benefit of those outside. After all, the Commander is
normally on the inside.
...I am not "allowed" to start the beacon until the ground agent has confirmed that I can!
Ermm, let me explain. I'm in charge, now P
ss off!
PM