The inference is that if an aircraft is on track then that removes the right to complain. Why?
Not the right to complain but who he can complain to and what he is complaining about. If the aircraft are following agreed and internationally published routings, then there it is not a lot the airport can do about it, and he neeeds to be taking it up with the CAA and the like.
If an aircraft is failling to follow the agreed routings, then the airport can do something about it.
It's like a new road being built at the back of your house and you complaining every time a car goes past.