If you can't do the static, how can you use aiki in a dynamic manner? This is "correct ukemi" to me.
Which brings up the question of why did Ueshiba want specific attacks and ukemi from his deshi? What drove that?
Ok, but is this too obvious to be right:
He wanted 'root' examples...with clear lines, which sprout to finer and finer subdivisions. Like a tree.
In simple words: Picked extreme cases that generate many possibilities. These samples/examples are the 'cardinal directions'. The foundations he chose...because they are compatible with the manifestion of aiki he wanted to emphasize.
What do you think?
P.s. Sorry; I think i owe you a couple of answers on other threads.
pps. You have a way with words, my friend. I thought you phrased the delineations between DR and Aikido well. I could not have put it so succinctly. I really hope that Shaun and others will address it, because I think there are a lot of unique perspectives assembled here.