While I liked the video and the characters overall, I will say I disagree with what seems to be the lesson at the end. While doing something solely for the love of it, learning not to lose heart by comparing yourself to others, and finding that both of these things can bring a unique quality to one's work is something I can agree with, I do think it under emphasizes the value of self improvement and the value of critique.
I think the issue is that Kattwerp doesn't just love doing art, but performing that art for a crowd, meaning they're asking for participation in their art without consideration for whether or not that participation is an enjoyable experience to the participants. Additionally, upon learning the crowd dislikes their music, they don't resolve to improve at their craft, to push through their rough edges, but rather to declare themselves great as is, reject outside criticism, and continue on as normal. This might have even been fine when on their own, but having the audience suddenly enjoy the same product they previously despised feels off.
Again, I liked the video as a form of entertainment, and there are worthwhile lessons to be found in it, but I think it falters on the landing.