Re: Beginners should not be allowed to act as uke.
I, of course, agree with most (if not all) of what you've said, Peter. It seems to me that some respondents might be bringing other factors into the conversation. (Naturally, I reserve the right to be wrong.) To illustrate my thoughts on this, let's take this out of the dojo and into a slightly different educational context.
I teach ESL at a major university. My classes comprise virtually 100% international students who are in the U.S. for the purposes of getting into this (or other) university. Many of them have conditional acceptance (i.e., they are accepted under the condition that they improve their English skills). That's where I come in.
Sometimes, my students are rank beginners. Sometimes, they are very advanced. However, in all cases, I am clearly the senior. As we say in my dojo, "I have the 'stuff'." I *do not* look to my students to improve my English. When I want that, I talk to other native speakers who are sharp enough to challenge me and push the boundaries of my vocabulary, critical thinking, and understanding of grammar. (Or, I just read Mad Magazine.) These are different educational processes.
What I *do* learn from my students is not only how well *I* understand the subject, but also how well I am able to *convey* that information and lead students into demonstrable results. As they progress, they need me less and less, and actually become quite capable of helping themselves and each other.
Ultimately, my responsibility is to teach them to not need me.