Earlier quoted context omitted.
Motive is the big reason. It's not like America is killing people for fun or some petty economic gain. America is killing people that American believes they are at war with. Hell, America is killing people who believe themselves to be at war with America. But drones only work when you have total air supremacy. Any halfway decent airforce can protect against the huge drones America fires missiles from.
It's not like America is killing people for fun or some petty economic gain. How do we know this, again? The folks who have said this are legally bound not to say anything else. So they're not particularly believable. The Snowden revelations about PetroBras hacking somewhat (but not totally, admittedly) makes me very suspicious that network penetration goes on for petty economic gain. Why wouldn't that leak into dron…
As for economic gain (not sure what is meant by "petty" economic gain), that has been a large part of the source of most international conflicts over the past few hundred years anyway. So that just sounds false.