Hmmm... I have been advocating that Kenbi is annoying, and I still think that... but I knew there had to be something more in there.
I mean... let's not forget... these are kids; I can't be angry at kids in a story like this. Despite being a "sports" manga about dance, this has always shown that everyone is a person; they have their stories, they have reasons for why they are who they are, even the bad sides are just one side of the whole, and that is without considering the depth.
I actually respect the author even more now... I had the suspicion, but without story development I couldn't know how deep it went, but Kenbi is Kabo's foil... so to speak.
There had to be something about Kabo's family life; he didn't talk about them, passing mention or not, and him having a stutter... you don't need to be Sherlock Holmes to infer what can come with that... but unlike Kenbi, Kabo still must have had emotional support, maybe from his mom; maybe despite his father's emotional abuse, it wasn't so extensive or constant that he didn't have time and space to develop.
Point is, that Kabo was able to develop at least somewhat healthy, and when push came to shove, he is able to appreciate new discoveries and not get inflexible with his decisions.
Now Kenbi has two choices, both will have multiple consequences down the line of his life... he can accept the defeat and learn from it... or he can crash down.
Mind... none of them are definitive... he is young, down the line of both he can fail again or find success.