Piloted aircraft and pilots are expensive. Drones have no pilots, and are thus much less expensive. It is not economically feasible to monitor vast swaths of land with vast numbers of piloted airplanes. It is economically feasible to monitor vast swaths of land with vast numbers of drones.
But that's not an argument against drones, that's an argument against large-scale government surveillance.
Ignoring whether or not you think government surveillance is a positive, negative, or neutral, the fact that a piece of technology makes it easier doesn't mean that technology is bad.
Edit: I'm not an expert in either field, but I imagine a similar argument could be made against satellites. That doesn't mean we should have a filibuster against GPS and Sirius.
Drones are actually on par for cost with F-15-generation fighter craft (i.e. pre-F-22). Drone pilots (yes, they have pilots) are required to go through the same training as the other pilots (in the USAF at least, who operates most of them), they draw much of the same special incentive pay, etc.
So I'm not even sure that drones are really that much cheaper, except perhaps if it's feasible to remotely pilot a large number of drones with just a single drone pilot.
But either way, even a cheap drone is more expensive than a soldier with a rifle.
It's obvious that the training process for drone pilots is much less rigorous than that for normal pilots.
I haven't dug into the numbers, but I guarantee you that all else being equal, a drone is much, much less expensive than a piloted plane of similar capabilities. That much is also obvious.
