The fairness, I can see if the project has said "We are going to have fair lines!" and then didn't I think it would be ok if you didn't get many lines. . . but to graduate is still understandable.
As for poor mixing, some people (cough me cough) are really bad at mixing but still try hard to do their best and really listen to what other people say about their mixing and try to do it better. If they told you volunteer to mix and they say no because your mixing isn't very good when it's better than there's in truth, then I would graduate XD
Bad organization is, I can't even say how good of a reason it is.