this strikes me as a bit ironic...to be fair, isn't this usually what "The IP Crowd" (for lack of a better description) tends to do? And, apart from styles in communication perhaps, isn't this probably the main source of contention we see in these conversations? I know I tend to have a problem with speed reading on AikiWeb (and thus missing crucial bits), and so I apologize if this is another case of that, but from my incomplete vantage, this is central to the difficulties we see; more so than suggestions of profiteering (which I think are fairly easily shown to be false).
Well, I don't have any objection with someone saying that what we do isn't Aiki because of A, B or C technical or historical reasons. I do have a problem with objections that are based on an accusation of branding.
I find it hard to believe Tomiki Sensei didn't transmit his understanding of aiki, but based on what I've managed to read, "the goods" do take several years to really develop. Not that it cannot be developed within a few years, but to be "good" (whatever that means) it takes considerable effort...a huge change in day-to-day use of the body, which I assume (and maybe you know what "they" say about assume-ing) most people aren't willing to adopt.
...thinking of the notion that this aspect of Aikido training is somewhat self-selecting (i.e. it takes a degree of commitment that is easy to miss).
It's certainly self-selecting. I would have loved to meet Tomiki - but I never did, so I couldn't say what he got and how much. A lot of people that I've met got something, some of them got a lot. However, getting a lot and being able to transmit it in a way that is self-sustaining is very difficult, however much you got, IMO.
It's interesting to note that one of the reasons that Sagawa believed that Takeda had created Aiki himself (rather than inheriting it from a long tradition) is that he believed that it was too difficult to transmit reliably over multiple generations. I'm not sure that I agree completely - but I certainly see his point.