Democracy is imperfect, but dictatorships are worse.

As for humans needing to be employed : autonomous return fire drones are going to be very expensive to build and maintain. That "expense" means that the labor of thousands is needed somewhere in the process.

I honestly don't think this is the case. Hobbyists working on their own with limited budgets have made autonomous paintball guns, as well as all sorts of other robots and UAVs. Conceivably robots could be incredibly cheap, much much cheaper than the average soldier.