Why photographing airports is banned if everything is perfectly pictured in Google Maps? While staying at Premier Inn, next to Abu Dhabi International Airport (AUH/OMAA), I was more than surprised to find out warning signs that I'm strictly prohibited from taking photos of the nearby airport form the hotel's roof pool.

Can someone explain me, why such regulations are still in place or how do they aid to airport security, if everything (what I'm banned from photographing from this distance) is perfectly pictured, in a far better details, in Google Maps?
I believe the sign is to prevent plane watchers from gathering at the spot and taking pictures of every aircraft taking off or landing, which, judging by the existence of the sign, is not how the location is intended to be used.