This is an absolutely perfect example of self-defense versus sport. Obviously a groin kick is against the rules in MMA for very practical reasons. It's extremely dangerous and can do permanent damage. But there is another reason you could surmise, that is more pragmatic. It's too effective, lol. The fights would be over super quick and nobody would pay to see them, after a while. And like you said, this is with cups. I've got a groin kick way back when with a cup, and yes, it still can put you down on the ground with your hands between your legs.
Now I would hope people get the point that this post is about the groin kick as a self defense move. The knees to the head when someone is on a knee, that kinda goes beyond self defense!
If you must exaggerate to make a point, then you're must not be very good at making points.
