Lost comms is generally not a catastrophic failure, however it means that you may have to wait an awful long time to get that "real-time data" the manufacturer promised you would get.
An awful lot of that huge new US Defence budget is going on UAV`s.
Maybe they price US lives higher than ours, (or at least can afford to).
Another point is how do you train with the things, especially in UK airspace !.
Many a poor Gazelle pilot has been sent aloft with a video camera, simulating a UAV.