I'll take a stab at this.
As far as the sports world comparison. Plenty of pretty average players have been great coaches. Lou Holtz comes to mind. Bobby Knight was a much better coach than a player. Generally speaking a coach is older and physically past his or her prime. I think that changes the comparison quite a bit. There will come a time when Rob Leatham will not be able to compete with the big dogs. He still has plenty to offer in the world of shooting pistols at that point, and his credibility has long ago been established. Most would understand that.
I have known some head coaches in high school sports that never played or wrestled the sport they coach and have great won/loss records and have put a ton of trophies on the shelf. But in those cases there are usually great asst coaches or volunteer coaches who provided the fundamentals or the technique, or the program won on talent and would have done much better with the technique or fundamentals.
I have run across many who cannot shoot now, and have never been able to shoot in the past, but want to instruct or are instructing. That is different and it is not acceptable.