sorry steve, but i have to disagree with you on this one;
Guitar Hero's campaign was meant to be silly, all the guitar hero games are silly. if you remember at the end of GH3 when you have to fight lou in hell, and after you beat him you ascend to the tower of rock and play some dragonforce through the credits. how silly is that? the best GH campaign i've ever seen though is GH Metalica i personally like that tone because it makes the game more enjoyable.
there's also a few points you've overlooked for GH6...
-the game was going for a Heavy Metal theme (i still don't know why they threw in those soft ones, you're totally right) but the metal makes the story a lot more silly, but it was awesome. i'd rather fight demons with the shear power of my metal to defend the ancient ways than play shows for money.
-the story was written by Dave Mustaine (lead singer and lead guitarist for MEGADETH) that's worth something, right?
-the story made sense: fight through the forces, find the ancient weapon of rock, and defeat the metal beast to save the world, EPIC.
-dave mustaine wrote a special song just for GH6, sudden death. super hard, very fast, very megadeth. it was badass
-narrated by gene simmons, the god of thunder. makes sense, right?
the game tried harder to appeal to the fans that fell in love with the franchise's most popular game, Guitar hero 3, which was easily the best game in the entire series. i'm glad they did to, the setlist turned out much better than in previous titles, but i was still diapointed that they didn't hold true to the metal theme and threw the entire rush album 2112 on there. in an interview, rush said the album really fits the story of GH6, and it kind of does, but that doesn't escape the fact that it isn't metal. the song Painkiller by judas priest would been more suitable, that song much more accurately fits the story of GH6.
in lamens terms, you gotta give GH6 a bit more credit, critizing it for the thing it was going after is way too harsh. silly=fun and fun=video games. never forget that steve butts, never forget that. video games must always = fun