Let's not get crazy here. MMFR is not "art." :hihi:
With that said, I don't mind some mystery in a story, but the whole thing can't be a mystery just a bunch of action--at least not to me.
They could have left some mystery, but still developed characters and the story. I don't need to know the background of the guitar player, but I would like to have something for Max and Furiosa.