And what is the result on the character of Nage if his attacker is falling down every time for nothing? He creates in his head plenty of false ideas. I.e. I don't need to use the muscles to throw somebody -- of course!!!! Uke is jumping down by himself! And because of constant repetition of the success, the physical feedback from uke reinforces this idiocy. ...
So Janet, what exactly did you learn with 90% of success? After all these long years of training, can you face with confidence stronger, violent, full of hate, possible with weapon, attacker on the street?
You are positing an extreme in which uke detaches and falls down. Did I ever say that?
I am positing a moderate training path in which uke stays attached and gives feedback, body to body, appropriate to the level of the partner. Incrementally correct movement by nage shows as a reaction in uke. Uke doesn't try to make nage fail - uke's body guides nage to correct movement.
Note the OP is talking about folks who are still working on basic kihon waza. An attack that is always faster and harder than can be handled is not a learning experience.