Yeah, the Black Album came out then, but it was kind of a last hurrah for that kind of music. Metallica, while achieving commercial success, hasn't really been able to re capture that sound (or anything like how they sounded before). Maybe that's due to the absence of Cliff, or maybe it's James' progressively worse vocals, or other things. Megadeth has continued to rock, but nobody really paid attention (not that they ever had the success of Metallica, of course).
I think there should be a place for upbeat music in the rock world. Maybe not to the extreme we saw with some bands, but it sure would be nice to hear something less depressing again some day. But that has been relegated to the realm of teeny bopper pop music. Unfortunate, in my opinion.