Sorry you can't see the point, I will try to explain it to you.
When you teach someone that while holding a position of authority or power over someone, it is okay to be cruel and abusive while taking advantage of your position or strength, you are abusing your position and basically teaching those under you to treat others the same way. Hence the many cases of Marines raping young women and children that have occurred, tossing puppies off cliffs, shooting wild horses for fun around Camp Pendelton, etc. If someone cares to study history, it is the same process that created cruel soldiers among the Japanese Imperial Army in WW2. They were blatantly cruel to those they oppressed, including the Chinese and prisoners of war captured in places like Bataan because that is how they were treated and how they learned to treat others.
Personally wrongwayric didn't teach them what they needed, he failed them, and while it is just my opinion, the first time he kicked someone under him in rank in the nads and not in self-defense, he should have faced Courts Martial. Do you think any troop under him could have done that to him and got away with it? It can be argued he was "preparing them" etc, but that is just an excuse for a sadistic person. That is why that type of treatment is in violation of the regulations. The Sargent Major failed the troops also.
Your point smells of something I stepped in once. Have you ever served in the armed forces? Have you ever had to trained to kill someone? Have you ever been in combat where real bullets were coming at you and you had to return fire?
If Wrongwayric kicked some kid in the nuts during hand to hand combat training because the kid was getting too cocky about himself, then he did the right thing by showing that kid that not everything he learned in basic training actualy applies in the real world.
I've been there myself as a young kid that thought I knew everything I needed to kick butt and take names, and my squad leader decided to show me just how much I didn't know. It hurt but I learned a powerfull lesson, and that was to sit down, shut up, and pay attention to what the older guys had to teach me.
Now back to some of the other comments you made, just how many is "many cases" of Marines raping women, tossing dogs off cliffs, or shooting horses? Abuses like that take place all over the world by many different types of people. Looking at the big picture the average of that type of conduct being committed by Marines or any other US service man or woman is FAR lower than the average of civlians doing that sort of thing. There are bad apples in any group and the military is very quick to deal out justice to those members that cross that line and are caught. The Service didn't teach those people that commit those acts how to perform those acts. It goes against the very nature of the armed forces and the code of conduct we are taught from day one and expected to live up to.
You "point" holds about as much water as a screen door.