We must remember that many language teachers went into teaching because they were really good at languages in school, and people choose careers in things they are good at. This explains the slowness of the change away from grammar.
If a child grew up being able to mechanically manipulate grammar in the same way that one is good at algebra, where everything happens in the left hemisphere of the brain, they will naturally, as a professional classroom language teacher, want to continue doing that way of doing things, the way that is directed toward the four percenters, when they become a teacher.
However, this is a disaster for 96% of the kids of these kinds of teachers, those kids who want to actually learn the language but cannot because they do not hear it in class.
We cannot fault the four percenter who does this – it is a kind of trick that has bespattered education for decades now. It is normal to expect that a language teacher would want to do things in the way that they were done when she was in school.
The problem is the 90% Use Position Statement and the Three Modes of Communication of ACTFL. Those sour the deal for the aforedescribed teacher. They cannot continue to do what they were doing. Their days of boring kids are over.