Aroa, what is your hobby? Dropping bricks on cars from overpasses?
The fact is that a drone can down an aircraft and a drone can now be bought anywhere by any idiot and flown anonymously by anyone, possibly with illegal intent. Unless there are strict and obvious limitations placed on their use, backed up by long jail sentences, there will be trouble. It is not a question of "public airspace". Is a freeway a "public recreation" area? Drone operators should be licenced and the drone registered.
To put that another way, look at what the idiots did with Green Lasers???? What do you think they will do with drones if they remain freely available to the same bogans????