If I understand correctly what you mean then it is a valid point, but I think the writer of that article is discussing something different.
For example, consider the art of foo-jitsu, which is mostly based around kicks and so suits tall people and is good for sport, or bar-fu, which involves shorter range open-hand striking and has some good ground fighting techniques, making it good for self-defence or for shorter people, according to the sort of classification I think you mean. Based on this description you would pick the system depending on your goal.
The focus article proposes that either of these arts may be used for any focus, depending on the attitude and goals of the teacher. So one could go to a foo-jitsu school that uses the same principles of art and base syllabus as the typical sporting classes found in the style but is oriented towards defence (its students never get involved in tournaments, for example), or a bar-fu class where the instructor has turned it into ground wrestling sport and concentrates on winning trophies. So, it is therefore possible to pick a class based on the characteristics of the system and find that the focus of the class is not quite what one wanted. The article states that there may be more than one focus but there should be one or two primary ones.
Of course, I may have misunderstood exactly what you mean; apologies if so.
For example, consider the art of foo-jitsu, which is mostly based around kicks and so suits tall people and is good for sport, or bar-fu, which involves shorter range open-hand striking and has some good ground fighting techniques, making it good for self-defence or for shorter people, according to the sort of classification I think you mean. Based on this description you would pick the system depending on your goal.
The focus article proposes that either of these arts may be used for any focus, depending on the attitude and goals of the teacher. So one could go to a foo-jitsu school that uses the same principles of art and base syllabus as the typical sporting classes found in the style but is oriented towards defence (its students never get involved in tournaments, for example), or a bar-fu class where the instructor has turned it into ground wrestling sport and concentrates on winning trophies. So, it is therefore possible to pick a class based on the characteristics of the system and find that the focus of the class is not quite what one wanted. The article states that there may be more than one focus but there should be one or two primary ones.
Of course, I may have misunderstood exactly what you mean; apologies if so.