Another thought here is what hard work is involved with the solo training offered by Dan (and others) and how long it may well take to achieve a level of proficiency that provides useful results, results without thinking. Many will not take the time and will drop the practice if they don't see results the following week or so. Some will see the level effort needed to even get started and be underwhelmed..... It is easier to be underwhelmed than do the time.
There is another perspective. This perspective is simply "would it be worth my investment of time". So let's say, Dan has some ability that no one else has. He's far better at it than anyone else. But no one knows exactly what Dan is doing, even Dan. No one has taken the time to really investigate what is happening, and understand what makes Dan's approach unique and "better". So you spend lot's of time learning what Dan is teaching you to do, but that's not actually what gives Dan his special ability. You end up wasting lot's of time, doing something that wasn't actually what gave Dan his ability.
This is the problem with "IHTBF". So you feel it, and it's impressive, and you want to do it. How do you learn how to do it? From nothing I've read here I Aikiweb can I ascertain what Dan is doing. When asked specific questions, all one gets in reply are references to Ueshiba, quotes from the Taiji classics, and lot's of talk of how it's been done in "open rooms" or how almost 100% of people now think this is best. These things don't tell us anything that about why "IHTBF" and can't be described in a coherent way.
Now I know among the "IP" crowd, there are red flags going up. Because there is this feeling that it has been explained, but it never has been. I would point to Hunter Lonsberry's thread "is aiki clash of forces" (http://www.aikiweb.com/forums/showthread.php?p=318999
) in this thread you can see where several attempts were made to get to the bottom of what people mean by the terms they are using. Very little was discovered. For example we never got to the bottom of what people mean when they use the word "dan tien". This is suppose to be a core principle in Dan's body method. Yet what the word is referencing is unknown. There are not standard explanations for any of the things that are suppose to explain what is happening. What are the duel opposing spirals made of, what do they spiral around/in/on? This a question that seems to be at the very heart of the issue, yet is never answered.
So why would anyone take on this practice, especially if it's going to take a long time to learn? If you were blown away by the demonstration of "IP", then maybe you are willing to take it on faith alone. Maybe, if you're a very trusting person, taking it on some "authority's" word, maybe enough. But I have been down the "trust me" road before, and I would like to see some proof that there are results at the end of the road.
When most "IP" people are pressed about what they've learned I hear again and again, something to the effect of, "well I'm not really that good, so I couldn't demonstrate it, but you should see so-and-so". This, in and of it self tells me that the methods to train this body skill are not very effective, even if the body skill is impressive. After all the years of debate we've had, there should be hundreds of people popping up showing this stuff. Yet I only see the same small number of names presented again and again. Why would you devote yourself to a long training period, with so little proof that you are going to get anything from it?