Having read a LOT about this film, it should be noted that the director never tried to get the band's music, nor did he ever try to interview the band. (Check any of the many many interviews online, or on the film's website.) He set out to make the first rock documentary without music from the very start, in honor of the band who filmed a stereo speaker for 4 minutes for their first music video. A risky move, but one that worked.
And, for the record, a went with a friend who knew nothing of the band, and I swear he loved the film even more than I did, because he couldn't believe the stories! Made him a fan on the spot. So, I would say this is a great film for music fans. Period. You don't have to love the Mats! You just have to love rock n roll.
The best music doc I've seen since the one on Daniel Johnston.