Had a big argument with a coworker about that this week, actually. What's usually brought up is that having a human being physically in the battle space affords you situational awareness and experience that just can't be replicated, as of yet, with a Drone. What happens if the enemy somehow cuts off the link between Drone and control? You can set the null to fly it back to home or wherever if that happens, but, generally, a human pilot can do a lot more than that - right now. I don't disagree that on a technical level Drones would be able to, eventually, out do a pilot in theory. They aren't limited by having to keep a human alive or conscious in-flight. But there are some pretty scary moral implications if we start affording more and more autonomy to Drones in warfare.

The question shouldn't be an "all drones" vs "all pilots" argument. It should probably be more of a "how do we intelligently and operationally integrate the capabilities of Drones into our strategic goals" conversation. That just doesn't seem to be happening with the F35.