Why is this film supposed to be great?

Rating: 4/10 (4 January 2016)

I am not a musician, just like to listen to good music. I understand that being a good musician takes talent and lots and lots of practice. We watched this film because of good rating. But after watching it, I do not get it. Why is this supposedly a masterpiece? Nothing really happens in this film, but a young man practicing drums and a old man using ridicule, insult, yelling, lies and deliberate manipulation to create great musicians as he states himself. While this all sounds romantic at first sight, the whole plot is ridiculous at second sight: It is not clear why the main character and especially other musicians allow the teacher to yell and insult them, just because he is supposed to be the best. While he is supposed to be the best, he HIMSELF admits (while being an old man, who supposedly has had lots of time already) that he still did not find or create the next great musician. In addition to that we learn that one of his fellow students committed suicide. Because he considered he was not good enough? It is not clear what story the main characters have that makes them what they are. Except for the teacher, there is not much acting from other protagonists. There is not much drama to show, except for the blood in the hands. And that has been shown a lot, I got an impression that drumming is a very bloody music.
I also felt that the film was low budget. There is only one good actor, the teacher. The set is simply a room or two in some university. Even the audience in the epic final performance looked fake.
In this sense, well done: No budget, no story, no acting. An ineffective and dangerous teaching strategy sold like the path for a great musician, gets lots of positive critics and awards.