Steve
Mostly Harmless
Obviously, there are kids who play sports because they want scholarships or because they have natural talent that they want to develop to progress to a higher level. There are also some kids who play for fun and exercise. However, if you are in a group class in karate, and there are some people (adults) who simply want exercise and some who really want to excel at MA, how would the instructor know the difference? How would he/she evaluate and instruct/correct, without knowing who is there for what purpose?
There are no definitive right answers. To me, if you are in a "class" then the object is to learn what is being taught. While some people may do some things better than others, there is still a point where something is being done right and when it is not. There are "cardio" kickboxing classes for people who are looking for exercise. So, maybe there should be cardio karate classes, as well.
I think you answered your own question. "How would he/she evaluate and instruct/correct, without knowing who is there for what purpose?"
The answer is, "if you are in a "class" then the object is to learn what is being taught. While some people may do some things better than others, there is still a point where something is being done right and when it is not."
It's really that simple.