FWIW, I agree with all of the above completely. However it does leave one area out. The folks in aikido who have made special effort to have internal strength placed squarely at the heart of the aikido that they do. Can't think of anything more irritating than being told you've lost something you haven't
Of course what then happens is that the guys from outside come along and say you're not doing this, I reply, actually yes I am and it gets assumed that I can't possibly be talking sense as, after all "aikido has lost this".
Well, isn't that what a lot of these conversations are for..... describing the how's and why's of doing things, establishing a baseline discussion level, etc? I know full well what you mean about some un-named outsider coming along and not realizing how great and perceptive you already are, but in my experience the real problem is far more often that some guy has self-perception disorder (SPD) about what he can really do.
During a workshop, I will have felt the movements of everyone, and pretty thoroughly, during the first 15 minutes. I pretty much know what they can do because I can feel their level of using "Earth and Heaven" for power, how well-connected their body is, and whether or how much they can actually use the dantien as an automatic control point. I won't bore you with the statistics of what I usually encounter, but I will say that during and after a workshop the number of people who have successfully done most of the exercises and who decide that "they could already do that when they got here" can be staggering. And what's so funny is that it's not just me that catches sight of it.... so do a number of the cold-eyed other attendees.
So my comment would be that this forum would be good place to lay out some basic and original commentary if someone wants to establish his status of "already knows this stuff". Go for it. And yes, the reason I'm being a little acerbic about the subject is that I find (IME) that not only can a lot of people do much less than they think they can, they also put the weight of that faulty perception on their own students and convince those students "you don't need to go anywhere outside of this dojo to get all there is".
In short, my point is that if you want to discuss about how much is already known, not known, whatever, please do it freely an openly within the Aikido community. Tell what you know; show what you know; get out and meet people and most of all, encourage your students to be aggressively collecting all that they can. All that openess will do wonders toward correcting an error that has been allowed to get out of hand in Aikido.