I hate to be the one who brings up such an apparently shallow point, but in my observation, the teacher whose image most closely matches the expectation of the prospective student is the one who fills the classes.
Of the many teachers I've had over the last twenty+ years, the one who attracted the most students was GJN Nam Hyong. He is a phenomenally skilled martial artist, and so I don't want to verbally take anything away from his ability to perform or teach. But he really looks the part of the wise old master (and it's worth repeating: he is) who has all the secrets and he had no trouble finding students. (Sadly for me, he was so successful he built up his Chicago school to the point that he sold our local studio so he could devote more time to it.)
So I respectfully submit that to particular segments of students, the classroom experience, including the voice, appearance, style and personal magnetism of the instructor are MORE important than the content of the class or the effectiveness of the techniques. This is probably the source of a lot of the differences we're discussing, IMHO.
Personally, I want the best technical instruction I can get. My teachers are all perfectly pleasant, but that's sundry to the point of the class at my dojo.