"Surely failing to graduate in an environment that places everything on having a paper diploma, including one's own image/self-worth, is more to the point of the suicide."

I can't speak for the parent poster but my criticism of the film is not with the themes, but with the trite way in which they are portrayed. I can't imagine an audience not understanding that this is what the filmmakers intended them to take away from the scene, but I can imagine them being put off by how they went about it.