... However my opinion is that this approach is an illusion and dead end.
I am used to this opinion. I very often hear it.
I started this way of practice some six years ago. It attracted me so much, and I committed myself to it because it was the first time, someone showed me a way of aikido which didn't depend on ukes cooperation.
1) You are right: uke is expected to be "answering", to be responsive, to become very flexible and soft. So tori can experience and explore his own body and the connection to uke.
2) You are wrong: uke is not made to please tori and make his waza work. On the contrary he is expected to clearly show tori his faults. And the more advanced uke and nage are, the more "heavy" uke will be.
3) I am used to practice with experienced judoka. I experienced this certain way of aikido to work on them. I could take balance, I could control them, I could throw them when I had started to change my aikido This was mostly not possible, with what I had learned and done for the first twelve years of my practice.
Yes, you are right insofar as this way of practicing involves the danger to lead to a totally harmless way of aikido.
But isn't this a danger in every style which works with kata practice?
No, you are wrong insofar as you call this way a dead end. ...