Couldn't agree more, I have over 1400 instructional hours to my name, and make a real effort to teach 'basic fundamentals' rather than 'Iain's pet peeves'. Its quite funny though, I do have to pinch myself sometimes when I'm about to open my mouth.
It doesn't just affect the basic PPL'er though, I recently strolled up to an aircraft renter who inisted in a checkout (I imagine for insurance). The CFI who checked me out was a typical 'my way or the highway' instructor, I smiled sweetly, did it his way, and had a little chuckle to myself!
Fellow instructors, please think before you open yer gob!