This is a perfect example of a very good execution. The movie is directed and produced and acted so beautifully that you forgive it for every plot holes, every stupid thing that doesn't make any sense in this movie at all.
You enjoy this movie because it's fun and will forgive it's downsides because as Glenn Holland said in the movie Mr. Holland's Opus (1995): "Playing music is supposed to be fun. It's about heart, it's about feelings, moving people, and something beautiful, and it's not about notes on a page. I can teach you notes on a page, I can't teach you that other stuff." Similarly making a movie like this is supposed to be fun.
You enjoy this movie because it's fun and will forgive it's downsides because as Glenn Holland said in the movie Mr. Holland's Opus (1995): "Playing music is supposed to be fun. It's about heart, it's about feelings, moving people, and something beautiful, and it's not about notes on a page. I can teach you notes on a page, I can't teach you that other stuff." Similarly making a movie like this is supposed to be fun.