I'm not a huge Nirvana fan, but your position on them is just silly. The helped usher in a new era of music during a time where rock was completely boring, tired (e.g. late 80's rock, hair metal, etc.). They brought simplicity and emotion back to music.... raw and introspective. Bands like Nirvana, Alice in Chains, Soundgarden, Smashing Pumpkins, Radiohead, and (as much as it kills me to admit) Pearl Jam... all to thank for brining rock back into the limelight.