As a teacher (junior high social studies), I don't really want others evaluating my ability to teach except for the kids that are/were in my classes. They are the ones that have the most experience with the way I teach.
Also, real historians go to the primary sources as often as possible. Continuous interpretations create a "telephone game" effect.
My point can be summed up with a question: If you want to learn about O'Sensei, are you going to buy a book written by Joe Blow Aikidoka, or one of O'Sensei's direct students?
Just a few of my brain-droppings . . .