I guess I see this a little differently than most. If you already knew how to fly then all he really needed to teach you was the operation of a glow motor. Starting, tuning, etc. and discuss the characteristics of a glow powered plane relative to electric power. Past that you just needed to be checked off that you were safe and met whatever flying criteria the club has.
There are two sides to every story and we don't have the instructors. Did the instructor mean that he/nobody else used rudder on takeoff at that club (which I would have a hard time believing) or did he mean while in the air? That's two different things and we don't know what he meant, because we don't have his side of the story. These aren't full-scale planes. They can be flown (in the air) w/o rudder successfully and that skill picked up later. That's how I learned so I know.
I have seen and experienced the sacrifices a club instructor makes. I will give them the benefit of the doubt every time until I have the WHOLE story.
(Not sure why this says In response to escontrol. It is just a post.)