.. the last real shock with a solid substance in music and not only.but i didn't want it get lost in the dust, some few posts and then dead .. so if some think it's worth to open a topic .. lets do it!
coming to your statement it's hard to frame grunge music in a style, to put a label (some of them really hate to be labelled).
trying with the main 5 bands lets try to say some influences
Alice In chains / Soundgarden heavy and Black Sabbath influence
Nirvana punk i should say
Pearl Jam punk-rock mixed with The Who (the hardest to define in my opinion)
Screaming Trees psychedelic hard rock
at least at the beginning then things evolved
then lots of other "minor" bands (but very important for the movement), such as Mudhoney, Melvins, U-Men, Green River, Skin Yard and on and on, that incorporate the above said elements and others.
one thing put them all together .. the attitude towards music and how it should be .. just music .. basic instruments and lots of energy deep emotions meanings and so on .. and the attitude towards live concerts .. amazing energetic adrenalinic.
cool how all the bands, almost, were really connected together.
i stop here .. uhm there'd be lot to talk about it .. i would really have liked living in Seattle in the late 80's-early 90's!
(have you noticed you have a pm Matt?
) 
Does it really matter which shelf they're at on the music store? 