You make a good point Tim. I think its important to strike the right balance of having the skills to teach and impart knowledge as well as a good understanding of the subject matter. I do a fair bit of training at work and find that knowing the subject matter is important but totally agree that the ability to present is equally (if not more) important.Call it what you like: teaching, training or instructing. It's the ability to pass on skills and / or knowledge to others.
Having experience of the subject doesn't automatically grant you the ability to pass on that skill or knowledge.
That's my point.
I am always trying to convince others with the knowledge to get a teaching qual ...so they can do it instead of me