In what other field of life are novices taught by anything other than well-qualified, experienced people?
Errmm - schools? In fact most areas, really. The experts in many fields do not go into teaching, and it is left to a sub-branch who have little experience of the real world. At least in aviation there is a core of instructors with experience, and at least we are only talking about private aviation, as most CPL instructors
do have commercial experience (I believe it is to be made a requirement for new CPL instructors).
My take on the debate is to teach the club's standard techniques (clubs with in-house trained instructors have such things!) but accept anything that is a standard practice and safe in someone I have not taught. It might not be what I teach, and I might prefer my way, but I know that there is more than one way to skin a cat. A reasonable comparrison would be a CPL test with a CAA examiner. In the navigation section the examiner should pass you if you use any reasonable claculation technique (and you find your destination). You only fail if you use no technique or if your technique is not valid or unsafe.