I'm gonna go out on a limb here, and talk about lack of training - which is really experience, too, but not on-the-line kind.
When I was trained as an instructor, I was given a lot of training in "bad landings". BTW, that used to be in the 61.87 student solo requirements. "Recovery from bad landings, and go-arounds from the flare." That was removed, in '97, I think.
So, of course, since it is not in the PTS or in the 61.87 regs, it is not taught to student pilots anymore, and appearantly not to flight instructor candidates either.
But it is still a critical point to teach. Instructors should be well trained in appearing calm and not hovering around the controls, but cocked and ready to instantly, like a striking snake, grab the controls inches before impact to recover.
We just don't make'em like we used to.
God, I sound like an Old Man.