Interesting conversation. Sort of mirrors an in-depth discussion that took place amongst the evaluating facilitators (those who train and certify climbing instructors in the FS climbing program) at the end of our climbing instructor's workshop this late spring...the one right after the WCGTG, that Pete McTree attended with me.
The point under discussion was whether an instructor candidate who was satisfactory at instructing, safe, and competent, but whose climbing skills and thus the range of his instruction was limited to "'old school" techniques.
He was teaching methods that are all recognized in the USFS Climbing Guide as suitable. His students were able to accomplish the climbing tasks that they needed to be prepared for to do their work. But the scope of available equipment, techniques, etc. that he could not expose them to was rather broad. And they may well have ended up working harder to get the same things done in a tree than their peers blessed with a more up-to-date instructor.
We decided to certify him. But I had misgivings, and still do.
Pete's observation after he listened to the bulk of the back and forth was something along these lines...I'll risk paraphrasing him: in his view, to be a fully competent climbing instructor requires an individual to be fully conversant in the state of the art. The student whose instructor has less to offer, inevitably gets less out of the instructional opportunity.
I know this isn't really addressing Greg's basic thread subject, but I'll toss it into the mix to see where it takes the current discussion.