Well that's an interesting point. But, in aikido part of our process is to relinquish an ego-based point of view, so shouldn't the head just be considered another appendage? In other words any psychological issues with that throw reveal where progress needs to be made? Just a thought. Of course the safety is still my main concern.
Not only does nage have no need to grab uke's head or neck, from a purely technical perspective it's the most inefficient and ineffective way to practice non-lethal Aikido. Monty and Matthew mentioned it's popular with ego-pandering WWF because it simulates and satiates a representation of lethal violence. O Sensei didn't randomly exclude kubinage from his training. There's no separation between nage and uke. Whatever disrespect nage gives uke, nage gives himself. Progress happens when violence or violent representations are no longer normalized or justified. Our society, our culture, our language is filled with violence, but that's precisely why we're in this mess(reference to recent discussions in open topics forum nuclear thread).