Sorry, I don't mean to be a pain. I do realize that this was posted.
However, Taekwon-Do's original ranking system had 8 gup levels & 9 black belt levels. Since modern day Taekwon-Do did not exist till the 20th century, I would agree that much did come from & evolve from the other Arts practiced at the time. Since the Japanese had colonized Korea, the influence of the Arts of the Japanese Empire were very strong.
Now there is a specific reason for why ITF Taekwon-Do has 9 levels of black belts. I would copy my previous post, but do not know how. One may scroll above to find it.
So ITF Taekwon-Do does not copy, as they have 9 compared to 10 levels.
MY question is still unanswered:
What is the reason behind the WTF/KTA & Kukkiwon using 10 degree ranks?
If your answer remains they copied off the Japanese, then that is fine, but then I would ask WHY did the Japanese decide on 10?
Is there any specific reason written/documented for the use of 10 as their terminal degree?
If one does not know the answer, that is fine, as I do not know it either. That is why I am asking. But so far, no one has offered an explanation that goes at the heart of the question. Please forgive me for attempting to seek knowledge.
I would say we are beating a dead horse, but we are not, as no one has yet offered an answer, so I continue.