that's the whole point, they wrote lyrics that were not cut and dried "party anthems", they were introspective, deeply personal and meant many things to many people.
compare that with fucking "cherry pie" LOLOL...you don't have to be Freud to know what the guy is talking about.
and the rest of your argument just doesn't make sense. you just said Sabbath are the forefathers of grunge and metal, and there was no "compression" in the 70's yet they had that same guitar sound that was aped in the early 90's. you are proving my point for me, and using it as an argument...nice work.
I don't care about this dialogue about the deepness of the 90's, all I can say is if you think give it away by the chille peppers wasn't a party anthem your high, and kurt cobain would write about complete nonsense just as often as he would write anything about lyrics, and I don't even care about this part.
Actually my point was riff rock and throatier singing became more popular as a result of the tech, which is exactly what happened. Musicianship wise hasn't changed in over fifty years, you can here the bulk of licks played today by modern guitarist, back in the 30's more often than not. The only real change is the production techniques and the tech's availible. Big band gave way to jazz, because it didn't require large bands to make big sounds, which gave way to rock because it only needed a three peice to work.
In the 90's this sudden popularity of a made of style of music, was simply the types of things that sounded best with this technology.
We've all heard it, either you heard sandman or teen spirit in 91, and the whole world changed instantly, what it really meant was the same old crap, but you were wowed by the production techniques, even though it was the same old thing for some reason it was just magical.