Anyone can fly a quadcopter though? You can buy one right now for a couple hundred bucks off Amazon (and strap explosives to it if you wanted to).
If anything, the fact we’re not seeing random drones carrying explosives and diving into groups of people on a daily basis shows the vast, vast (99.999%) majority of people is actually well-meaning and has no desire to kill or hurt anyone.
If you’re legitimately baffled by a random guy being able to fly a quadcopter around without any kind of government approval or oversight, I encourage you to buy one and play around (without explosives please!), just make sure to not fly it over places where people could be standing - terminal velocity is real and even a light one could cause serious injury if it were to lose control and fall on someone’s head.
Or it shows mass surveillance is working so well as a deterrent. If we got rid of the cameras everywhere, someone might rig a drone with explosives.