I think it is true that if at a young age that a wrestler relies too much on one quick move to constantly pin opponents that it could hurt their development in the long run. I have seen young kids successfully use that headlock or head & arm throw (excuse me if I am using the wrong term because I did not wrestle in high school) or other quick pin moves from the mat. My son was fortunate I think in that he was not at an early age successful at doing any of these pin moves. In fact most of his victories when he was starting out came from points not pins. I feel this helped him to learn how to compete for an entire match. I think this is an important thing to learn because sooner or later you will meet up with someone who you are not going to be able to pin with your signature move.
As far as parents getting overly upset with their kids if they lose a match, I have also seen this. I saw a mother do this to her son after he lost a hard fought double overtime match to my son when they were both very young and novice wrestlers. I never saw the young boy wrestle again. It was very unfortunate and I am sure the boy would have been a very good wrestler. I think it can be a sure fire way to drive your child away from wrestling or any sport for that matter. We can give them direction, advice and encouragement, but we have to let them go when they step on that mat. This is where they become strong independent young men and women. We can help them on their way but we can definitely hurt them if we do not let them ultimately take charge of their own wrestling future.