Chuck you said
"For some strange reason there are a lot of people in aviation who think that holding an instructors rating is somehow an indication that the holder of said certificate is guaranteed to be a good teacher."
I would balance your statement by saying that a lot of people in aviation think that simply have many thousands of hours automatically makes you a good teacher. This IMO experience is often not the case particularly when teaching new pilots. The higher hours are simply an indication that you are probably a highly skilled pilot, but for instructing at the end of the course the only thing that matters is how well the student can fly.
Obviously in a perfect world the instructor should have both lots of experience and demonstrated high instructional skills. Students IMO should make a big effort to search for and train with those kind of instructors, particularly for advanced training (ie post PPL).
Effective teaching is a skill like any other. A pilot engaged in instructing, regardless of their experience will IMO be a better instructor if they undertake a course of formal training in the art of instructing.