You've just reinvented the air launched cruise missile.
A close cousin of the very popular fire -n- forget missile and the smart bomb.
Something that must be considered is pilots that aren't risking their butts might be a little more ... aggressive with drones. And drones larger than RC planes aren't any lighter or cheaper than manned craft (so you yank out 400 pounds of life support and cockpit, and replace it with 350 pounds of radios, satellite downlinks and computers. "Eh") So this agressiveness could make mission costs somewhat higher.