Nirvana's had an influence on more than just ****ty watered down alternative rock banRAB. Like boo boo said Radiohead've cited them as an influence and I know sleater-kinney have been, not to mention the general bunch of garage rock banRAB of the early 00's. Even if they hadn't been any sort of positive influence music, they made catchy pop music. They never claimed to do otherwise, in an interview Nirvana said that they made songs like children's songs, they're so catchy they'll stay with you forever. Brilliant lyrics are a matter of contention but there must be something for critics to point to the band as having great lyrics. Not to mention Bob Dylan himself upon hearing a Nirvana song said of Cobain that he had heart.