The question is, did the Founder actually have some degree of pedagogical skill? Did he deliberately refrain from disseminating information in order to maintain superiority, or did he teach to the extent of his ability unable to disseminate all the information he had.
I skimmed through all the many responses, I maybe saying the same thing as others. The Founder has passed away. The two questions have importance is to his direct students. I would suspect that if they never complained than this isn't an issue.
It's not an issue if it worked - if he produced people who were able to replicate his skills consistently and pass those skills along to their students.
If that's not the case (and, IMO, it isn't) then all this talk about how these are valid teaching methods is meaningless.