More planes in the airline fleets=more flights worldwide=more chances for birdstrikes so, using that rationale, more quads in the hands of people that don't know the rules+more flights in the air from all the various airlines=more chances for a drone strike with possible catastrophic results. It obviously doesn't take a PHD to figure out that as flight numbers go up as well as the number of quads in the hands of idiots, the chances of a mid-air go up exponentially