You think its BS, get on the mat with one of these folks. If you think you can do what they are talking about, show people you can. But sitting back and questioning everything in a discussion when you have absolutely no direct experience of it is ridiculous.
I believe that this phenominon is the direct result of aikido being viewed by its students as a commodity, not a skill.
I was walking down a boardwalk several summers back and there was one of those street vendors who paints a pitcure of the night sky using acyrlic spraypaint. The art is completely replicable and [a little] cheesey, but interesting to watch in creation. Anywho, I overhear a couple standing next to me, the man says to the woman, "that's so rehearsed, anyone can do it." Apparenatly the artist overheard the comment as well and announced to the audience the man should help him make a picture. The story ends with the man looking silly and skulking away. Things are not so easy sometimes.
In aikido, I an amazed at the number of questions, comments, backseat driving, and general discussion that takes place. In many cases, those offenders see aikido as a commodity to be used as they see fit - they are entitled to descriptions, diagrams, and elaborate explanations because they are paying for that knowledge.
Scientific knowledge can enlighten a difficult concept, but so can practice. Senior aikido people can better communicate complicated concepts, but they can also better illustrate the proper movement. Muscle memory is a very important tool for training and I don't think you use the right muscles when you talk...