I think it quite interesting that although Ueshiba M. had to go through the hard, nasty, grueling martial forging process of dealing with his own demons to get to where he arrived spiritually, that modern Aikidoka somehow think that they can start at the end where he left off without first gaining the same level of understanding of the true enemy that he had.
I am not in disagreement here. I think it funny that I am in danger here of being placed in opposition to the folks that cross train (which I have done and still do, as do my students) and am in danger of being seen as the representatives of some softer, easier Aikido. Any of the folks who know me would find it fairly amusing, I think.
Your post brings up a good question... it has to do with what one needs to do to follow after someone like O-Sensei. It's true that to duplicate his knowledge, which would be pretty much impossible to do completely, one would have to try to do all of the various things he did. That would include the life experiences as well as the training.
O-Sensei's focus changed over the years as his spiritual views changed. There has been quite a lot written about how the aftermath of WWII changed his thinking about things as well. When he started to put the finishing touches in what would be modern Aikido, I think he had certain things in mind. I don't not think that we have to go through everything the Founder did to follow the path he outlined towards the end of his life. If we were required to reinvent the wheel in each generation, we'd never make it.
I think that one of the absolute, fundamental purposes of Budo training is to help people lose their fear. Notice I say lose their fear, not simply overlay them with aggression and pretend they aren't there. Hard training is important in this regard. Many of the fears we have are about physical violence, being hurt, pain, etc. Aikido actually offers a really good way for people to deal with these issues in a way that is designed to be non-injurious. That doesn't mean sucking the life out of the training to make it user friendly. It means taking it right to the edge.
Somehow I seem to have given the impression that I am advocating some sort of Aikido that is in contrast to severe, hard training. I am not at all. I am not questioning in the least the folks who look outside Aikido for things that we are not very good at in our own art; I am constantly doing that myself.
My article was merely trying to point out that we need to stop apologizing for what Aikido lacks. Some of what it lacks, we need to get put back in , no question, but some of what it lacks, it lacks on purpose. I strongly believe that if one looks at everything from a purely utilitarian view of what will work in a fight, what will make me the unbeatable martial artist, then the essence of the practice will be lost and we will be busy devolving our art into its antecedents. We don't need to remake Aikido into Daito Ryu. Daito Ryu still exists and if that is what people want, they can do it. A devolved Aikido wouldn't be good Daito Ryu, it would have ceased to be Aikido.