[philh]

The military's job is (essentially) to save some people's lives by killing other people. It is a distasteful job, but (most people agree) a necessary one. Therefore what the military needs to be good at is killing targeted people with minimum loss of life to others. "Others" includes members of the military.

If drone guns result no more loss of civilian life than other methods of attack, but with less risk to the operators' lives, they make the military better at its job.

If there are too many civilian casualties, the solution should not be "make the military less good at its job". It should be "make the military's job less necessary".