It is really not surprising since there is no concensus on just what are the important things to learn to begin with. For one thing, it is not possible to devise such a course when the minds of educators are so dark to begin with.

If one is not clear on what a thing is, and what it is suppose to do, it is not likely one could write an instruction manual on it worth a damn.

When one has not, or can not, abstract a concept, then it does not matter if you use the linguistic construction involving that concept--they cannot comprehend what you say.