This is a shockingly high number when you consider that any male 18-50 with the target is automatically considered to be a combatant. So the real figure it likely to be considerably higher. Imagine if you heard that Vladimir Putin was sending agents abroad to assassinate people that Russia considered terrorists. But they managed to also kill innocent civilians every other time. I suspect most people would condemn that action. Is the drone war any different?
Not to mention that I believe the drone war is actually counter productive in the long term. Imagine you live in a village and regularly hear a drone overhead. Every few months it kills somone in the village. Sure, might have been a bad guy but that's not a great environment for people to live in. Only likely to create resentment and create more terrorists.
America seems to never learn from conflicts like Vietnam and more recently Afghanistan. If you sit in someone's backyard and kill people you create more of the people that want to kill you. Want to bet how many years the drone war continues before you realise it has not solved anything and your just perpetually creating and then killing terrorists.