I believe head shots are unethical. There is very little margin for error and it is definitely NOT a "hit or miss" situation!
Far too many times do you hear of someone being off with their shot, only to blow a poor deer's jaw off.
Ethical shots are to the larger kill areas of animals...heart/lung shots, shoulder shots, behind the shoulder etc.
Too many "so called" hunters believe they are showing off by shooting animals in the head. They are not impressing anyone.