His father complimented him exactly once - upon the completion of the new hombu dojo.
FWIW, I think that Kisshomaru had more "stuff" than he is generally credited with, but that he purposely set up a structure that would not transmit it - at least, in which it would not be transmitted by hombu. Hombu, in this paradigm, is kind of a blank - but it leaves space for people under hombu to do the real work.
In that sense, I think that he was successful, since that's probably the only kind of organization that could realistically survive as an umbrella. On the other hand, I think that it is important to realize that this setup means that the King has no clothes - they have to tailor things themselves.
Yes, I think you are correct. The great thing about Hombu back in the day was the tremendous breadth of instruction that was available there. I think the Dojo itself itself was really set up to allow the various deshi to develop their own Aikido. You could have a Yamaguchi or an Arikawa both teaching there at the same time. But the secondary purpose of the dojo was to train instructors for the future expansion of Aikido. I am not sure the wide variety of style and instructional approach at Hombu made the process of training future teachers very easy. In the case of teacher training, I am not sure the "it takes a village" approach is the best one. There evolved a certain homogenized Aikido that lacked the brilliance of any of the individual teachers. Sort of a least common denominator Aikido.
I think this is an avoidable problem for future organizations but I do not see any signs that the current powers that be at hombu see this as a problem so the issue not only doesn't get better, it seems to continue to go the same direction it has been. I think it remains to be seen whether individuals of great initiative and talent will rise above the general level. This is after all a Japanese system in which there's a certain amount of "the nail that sticks up gets pounded down" at work. That's why I am far more hopeful about what is happening outside Japan. There is far more freedom to innovate.