I must admit that it's only in my adulthood that I've come to appreciate Nirvana's contributions to music and pop culture. Yes, I was alive in the 90's but I was only 13 when Cobain died, and I was too busy doing the Macarena and watching Full House to get enveloped in the angsty, grungy Seattle sounds that were being played on the local radio station The Nerve. I knew the songs of course, but they were just part of my environment, and although I wore a healthy amount of flannel, I never listened closely to the lyrics of these songs.
The documentary doesn't really focus on Cobain, or his music; it's really dedicated to pointing out the inconsistencies in investigation into his death, and the stories surrounding it.
Cobain's wife, Courtney Love, hired a private investigator to find her husband after he fled from a rehab facility. That detective, Tom Grant, makes no secret about his suspicions that Love was not being honest about Cobain's disappearance, or their marriage.
I love reading and discussing conspiracy theories, but Grant denies that this is a conspiracy theory. It's certainly not as outlandish as some of the ones involving the Holocaust or the assassination of John F. Kennedy; this documentary is simply presenting a timeline of events, highlighting the reports and statements (by Cobain's wife and friends as well as lawyers and law enforcement) that are problematic to the suicide scenario that has come to represent the legacy of Nirvana.
Obviously, Cobain and his wife and their circles were heavily involved in drugs, and any kind of altered consciousness is going to detract from someone's credibility anyways, so that's another issue involved when Grant was interviewing people around the time of Cobain's death.
The note in Cobain's writing, commonly believed as evidence of his suicidal intentions, is heart-breaking to read. It's not heart-breaking because it led to the end of a favorite band, it's just always heart-breaking to imagine any person who has reached a point where they believe death is the best option. I cannot imagine how much pain a person has to be in to consider it.