That is to say, the art that is supposed to reconcile the world, that is supposed to unify things, is surviving through the years by practicing huge amounts of exclusion and partition. It is like the art has to sell its soul in order to get into Heaven.
Well, I don't see it quite that way. It's pretty clearly known in most dojo where I've trained who you can go to for this more honest, more challenging practice. It's usually clear just watching people train after an advanced or even regular class. I've had members of 'the group' reach out to me to invite me in...and I'm not much for belonging. I''ve seen them welcome anyone who wants to step up to that next level.
Another issue is that it would be great to behave that way with everyone in the dojo, all the time, no matter what. But the problem is, aikido isn't a koryu, you have many different types, and supposedly aikido has room for these different types. Some people are actually happy just doing the kata, and not much more. Many beginners will quit if all they get is thrown (before they can fully protect themselves), and they never get to throw.
What do you do with the student who has a resistance to falling, and it's creating a safety issue for them? I would tell them to take every fall, no matter what. Take the fall enthusiatically, just dive right into it, learn to love ukemi by taking ukemi. Later on, when they are safe, they can work on resisting, being hard to throw, reversals. Step one: ukemi. Is that a valid method? If so, what does it do in terms of this discussion? I guess I'm just not convinced everyone can get 'there' safely right out of the box.