I feel like the visceral reactions people have to ground and pound is largely a byproduct of the notion that once someone is on the ground, they're incapable of defending themselves. Those of us who watch substantial amounts of MMA know this not to be true, and that the guy on bottom, especially if he has full guard, has a bucketful of joint locks and chokes at his disposal that are just as menacing as the top guy's strikes.
I would hypothesize that someone coming from a CMA background would have this misconception even worse, due to the "I threw you, therefore I win" attitude of San Da and Shuai Jiao.
I understand that a guy on the ground CAN still defend himself and win a fight, but this is usually when the other fighter is also on the ground or limited in how they can attack their downed opponent. And while I am not by any means an expert it seems with few exceptions that throws are meant to leave 1 person standing and 1 person not which leads to my above observation.
I hate to reinforce the street vs sport crap but there are some rules in UFC that while designed for safety and entertainment inadvertently encourage bad habits. How many times has a ref had to warn against hitting the back of the head? That guy who gets warned should be given a strait win because he is in the position to deliver what could be fight ending strikes but isn't allowed to by the rules. I believe this is the core of what JC is trying to get across. If there is a point at which someone likely would win why allow an unsavory aspect of fighting to continue (for the sake of entertainment) rather than stand up and begin a "new" fight.
As far as hitting to the back of the head goes, I know its illegal. I was actually thinking about the fight between Royce Gracie and Matt Hughes, at the end where Hughes was on Gracie's back and throwing hooks to the sides of his head until thre ref called it.
I was out at a bar watching it with my Sifu that night, and that was when he commented on how it was a poor example of honorable fighting and that kids would try to emulate it.