Nirvana were shocking in their rip-off of the Pixies.
And Grunge simply revealled to record companies that Agnsty music would sell millions (Nevermind...) which produces the crap EMO we have nowadays like Avril Laviegne talking likle the whole world is on her shoulders...Nirvana created her.

The best Grunge bands were the ones that transended Grunge like the Smashing Pumpkins or indeed Pearl Jam