Do you want to be taught math by a mathematician, in other words, by someone actually engaged in doing math, or by a math teacher? Do you want to be taught poetry writing by a poet, or by a teacher of poetry who has read a textbook on teaching Creative Writing? Do you want to learn history from someone who does historical research, who is engaged in finding out answers to the kind of questions historians ask, or by someone who has learned enough history to teach it at a lower level?
Are these all the same question? Does the level of the class matter? Your reason for studying the material? At what point does pedagogical expertise become less important than knowledge of the subject matter? If ever?
Is there a fundamental difference between high school and university instruction? Could we introduce the university ideal at a lower level of instruction, so that the student would care what the quality of mind is in a high school teacher? Or is this kind of concern going to be increasingly rare even in the university, where you don't start caring about that until the first two years of "developmental" education are done with? If we cease caring about the quality of mind in the instructor, then will this eventually become the norm even in graduate education? After all, there we are training instructors, and those instructors need only know enough of the subject matter to transmit it to the next generation efficiently and unambiguously?!? @#%^^#@^^%@#%!!!