I had a similar thing in college where a algebra teacher was let go due to having several entire classes get D's and F's. I'm bad at math in the first place but I've never failed a class to the point where I had to retake it. Luckily I got a withdrawal so the F was dropped. And yeah, it doesn't help that he went to a military college and served 13 years in the marines, so 17 years total living in a military style environment. That probably plays a big part in why he is like that, as well as other things too.