Anyway, I'm getting the feeling that this is one of those threads where the poster has made their mind up in advance ...
Yup...
And the reason it hasn't gone the same way to a similar thread is that the OP has taken care to seem, initially, reasonable and open to opinions -- but the AIBU itself is formed so that one answer seems natural.
Were I and my 'chatty' fellow students being unspeakably insensitive and spotlight-hogging? Or was I being reasonable, and actually, active interaction and participation is what MA tutors wish to see and students ought to expect to do?
The contrast between 'unspeakably insensitive' and 'active interaction and participation' is too dramatic. Like a lot of people on this thread, I've taught similar-sized groups of mixed age and nationality, and there's obviously a margin of irritating behaviour before we get to 'unspeakably insensitive'. Do I want everyone to just sit there like a potato? No. Do I want to deal with the same person again and again -- the one who always has the question, the clarification, the anecdote, the correction? No.
It's not really possible to say YABU or YANBU depending on your first post it's the kind of thing where you really have to be there but all your subsequent posts (their detail, their frequency, and especially your barrage of questions to Kaki) do actually suggest to me that type of student profile.
And, yes, it's up to me to manage the class dynamics, but we're also all adults, and it would be nice for people to recognise their own behaviour and perhaps check it before it becomes an issue. But they never do. And not once, when it's got to the point where I've had to actually speak to a student about dominating class discussion, or constantly dragging us off-course, has the student ever thought I was being reasonable. It's always: but they're trying to help, they've got a good point, they've paid X in fees, all the other students are so dull, they're in the wrong group.
When you teach these kind of groups for long enough, you see this over and over. It doesn't really matter about age, although I do see it more with older, professional students, some of who have issues returning to a classroom environment: a lot of subtle assumptions about their own level of attaintment, their personal investment in the course, and how this relates to the younger class members and even, sometimes, the teacher. Some of your comments about your tutors are, for example, polite but patronising.
All of this is a minor but not insignificant irritation when managing group work, although -- in this case - it sounds an awful lot like the tutor's just given up and relies on the louder students to carry the lesson, with the rest of the students increasingly uninvolved.