You have put a bright light on the problem, and see the solution as having no worth. That is your privilege. Why did Funakoshi create Shotokan? Why did Kano create Judo? To a large extent they toook fragmented systems and codified them so thy could be taught on a large consistent scale internationaly. People doing that system could travel anywhere in the world and and find a home learning the system. General Choi did the same. If you are content with operating in your own little corner of the universe, and never intend to leave, and intend the same for your students, and really don't care that outsiders who may relocate to your area having trained in the system you purport to teach will be uncomfortable with the home gron changes then doing only what an isolated instructor teaches is fine.