I'd agree with this conclusion from another angle as well. It seems slightly odd to me that people think there must be a single "right" way to teach. What works for one student, one group of people, doesn't necessarily work well for another.

And it also goes the other way as well. One form of pedagogy might work excellently for one teacher, yet he may do abysmally at another. What's "right" for him may be wrong for another teacher. By striving for something like homogeneity you disadvantage not only students, but also teachers.

This is all even more true in current times as educational outcomes continue to decline even as ever more money is pumped into education, and teacher churn rates are at record highs, with many completely leaving the profession.