One of the coolest things about Nirvana, and Grunge in general, is that they rejected commercialism and the crass, out of control party s—t that was in rock from the 60s thru the end of the 80s. They would play at dive bars and talk to fans in person without the backstage thingy. Vince Neil of Motley Crue reportedly hated Nirvana and was pissed because they completely created a new genre of rock music. Every so often, rock music needs a kick in the ass, and Nirvana thankfully ushered in a new era.
But some genres and some bands think they're so much above the "the little people" that...well...I don't give them my money.
The grunge scene, and Nirvana in particular, often gets credit for killing glam metal. In reality, glam metal was already declining and would have died off anyway.
And while I did like Nirvana, to me they were the least interesting band in the grunge movement. I found Alice In Chains and Soundgarden much more to my liking.