Ginsu, there are conditions of quality. If it's a TV or something, then people are okay with that. But if it's something like music, then nope that's not cool. They like it so it just must be good. As well, there are things that explain music and can explain all music in pop culture. Pop culture doesn't even have anything that can explain its own music, let alone determine quality.
No, those bands aren't leaning towards classical 'style', as I mentioned. Yes on jazz fusion, but jazz is essentially a pop culture music so big deal. There's all kinds of stuff in jazz with ridiculous names that weren't new when they came out in it and weren't really a big deal anyway.
TOK, I've read up on Meshuggah (though I have the tools to understand what they're doing just by listening). They're not doing anything remarkable. Decades ago, composers like Phillip Glass were doing monophonic or parallel voiced repetitive lines that changed - but it was all within the bar line, which makes for very harsh rhythmic changes. Beyond this, there is no polyphony, no harmony in Meshuggah. There's little polyphony/harmony in most metal - and parallel thirds, fourths, and fifths don't count. As well, there's little syncopation, most of the meters (not times Ginsu - time is tempo) are 4/4, and in any case the bar line is a draconian boundary in this music - in most music in pop culture.
The best you're going to find is Cynic's Focus ('94) - and maybe their new stuff, which hasn't been released yet.
Oh, wait....Watchtower actually had some polyphonic, contrapuntal stuff. Kinda weak, particularly metal-wise, but definitely thought-out. And Atheist had some brief stuff on Unquestionable Presence.
Slayer: lame after Seasons of the Abyss. This is not any comment about the absence of Lombardo. They just played out their gig.
CoC: for those who didn't like their earlier stuff, Blind was great, and then they wanked into mainstream.
After Metallica's black album, a lot of bands followed suit - Testament, Megadeth, Sacred Reich, Anthrax after Persistance of Time - through about '95. (Even Pantera's Far Beyond Driven was a mix.) Even death metal was reaching a peak by Carcass' Heartwork, and really the death knell was Suffocation's Pierced from Within. You couldn't get any heavier, and nobody did anything smarter. Still haven't. There is a recent band Alaska whose members can read music and they score their pieces - but they're not composers and their pieces are generally monophonic and simplistic.
On the wiki thing: I felt they were asking questions pretty basic questions. If you want to nursemaid them, fine. I was merely indicating they had a resource other than you.