As a pilot myself, I know how replaceable the pilots are nowadays... the US army drones are now reliable stuff, but I also knows that everything is much more complex in the sky...
This is clearly a PR stunt. That none of the existing drones carry sufficient power to perform their tasks in an economic way is just a very small part of the problem. There are so many conditions I can think of that render a drone unreliable: rain, fog, strong winds,... small drones are not very capable devices: even an average wind gust can catsh it by surprise and smash it into a concrete wall just because it's not powerful enough to counter the gust.
All the demos you see are carried out in optimal conditions that are simply not available 70% of the time. And I'm not even mentionning other safety hazards, coordination problems if the drones traffic becomes important, etc...