How do you know that airspace won't be occupied? "Probably won't" doesn't make up for the fact that aircraft are operating there and may, in fact, enter that "safe zone" over the airport. At a much greater chance than an aircraft may appear over your house
IMO it's like saying I can walk across a road and I "probably won't" be hit by a car because there isn't much traffic. You may be right for the moment but it will not always be the case.
If the drone loses power or an engine and it's over the airport, where is it going to go? Chances are it'll fall into a movement area and become FOD, or maybe find someone on takeoff. There's no need to be over the airport with drones, it is a curiosity and nothing more. Why provision something to allow people to do it when it isn't necessary and is a safety risk?
Not saying ban drones from all areas of the sky because a plane might be there, but an airport or approach path is a no-brainer to lock them out of.