I doubt I am alone in still wondering why the hell Takeda taught his stuff ass backwards.
Nothing really to wonder about, I think. He was a paranoid man, who wouldn't even trust one of Ueshiba's students to hand him tea without demanding he taste it first. In a recent little article on AJ, I believe, neighbors in his home town described how if they crossed the property line, he'd chase after them and assault them (with many of them getting dislocated arms or wrists).
Can you imagine him allowing anyone to be in an even momentary position of advantage?
Also, the whole selling point of DR, and thereafter, aikido, is different. It's all about being--or appearing invulnerable. Throwing people with a just a twitch of the body. God-like powers. Just like the comic book ad that first got me interested - "throw people with mystical energy!" DR and aikido, at least among it's founders and leading lights, was an exercise in grandiosity, in posturing and impressing both onlookers and one's own students. As Stanley Pranin described to me when he visited the Sagawa dojo, as his students were being thrown, they were, while still in the air, exclaiming, "Subarashii!!!! Subarashi!!!" Quite apart from any level of skill Sagawa might have had, that he didn't tell them to shut the hell up says quite a lot.
BTW - one place that even koryu instructors will not take ukemi is hojojutsu (nawajutsu). I cannot think of any teacher, certainly publicly and even in their own dojo, who would allow their students to tie them up.