I've wondered the same thing. Let's just pretend for one minute that the Black album didn't come out and Death Magnet took it's place. Would the metal world be as split about Metallica as they are now? We may never truly know and we can theorize until the cows come home.
However, if this were the case, for me . . . I have a sneaking hunch that I'd still be disappointed with Death Magnet. Here's what I've noticed about this disc. The band seems to have lost the majority of their feel for epic songwriting. Justice had those majestic, sprawling instrumental passages that took the listener someplace. There are a billion memorable moments on that album. Magnet leaves me wondering if certain members of the band have just lost the fire to reach deep and perform from their musical soul. Kirks solos are all over the place, but never take the heart anywhere. Noodling for the sake of noodling. Lars overplays portions of the songs, almost as if to say, "Hey! Look what I can do!" but completely playing out of context of the song.
I don't know. Personally, I feel like the band was trying too hard to sound like the band that they used to be rather than be the hard ass mo-fo's that started a revolution. Is it a terrible album? No . . . not by a long shot, but it is far, far, far from their best. That's all. I've said my piece. Up the irons!