1. Kurt Cobain isn’t Lady GaGa, and that’s the idea. Cobain was a real guy, with real emotions that came through in his music, exposing his audience to actual human feeling. Since that is the ultimate goal of music (not “to help you look cooler”), it’s a huge part of the appeal. And since he happened to be the tormented sort, his voice conveyed that, very effectively. In fact, he used his voice as a way of separating the fans who understood his music from the ones who were just coming to shows because it was cool – and the result was heartfelt songs that sometimes sounded quite ugly. Some people who claim to be into rock don’t like that, which is fine. In that case, you can go back to the cushy drivel you’re tricked into buying by fake guys who drive Land Rovers and have no reason whatsoever to actually feel the music they make. Your loss, smart guy.
2. Kurt Cobain was indeed a junkie. This wasn’t good for his health, but the ironic side of it was that his drug habits made his mind go places people don’t normally go, and his songwriting brought it back for everyone else to see. Because, as unfortunate as it is, junkies actually tend to write better songs. Doubt it? Go ahead and listen to “Come Together,” “Space Oddity” and “Something in the Way.” Now go listen to Jet. Or the Jonas Brothers.
3. Nirvana is indeed simple and raw. It was the ’90s, and simple and raw was a reaction to pompous and flamboyant (like Guns ‘n’ Roses). And since Nirvana was so raw, basic and new, everybody else did what they do with anything — they copied it and made it prettier. Hence Pearl Jam, Silverchair, Bush, Filter, and all the way up to the pretty-boy, fake “grunge” bands that are around now, like Seether and the screamier parts of Linkin Park. (Don’t even get me started on them.) Those bands took the same idea, made it cuter and more produced, and added stuff like extra testosterone, Abercrombie-Fitch fashion and hip-hop tendencies, so it could become much more popular. And it did. So, when you go back and hear the original version of all that pretty noise, on the surface it can be underwhelming — like how Joy Division’s version of “Dead Souls” isn’t quite as hard-ass as Nine Inch Nails’, or how Donnie Darko doesn’t have quite the same level of drama as its sequel, S. Darko. (If you haven’t seen the sequel, don’t bother.)
4. Nirvana preserved pop, despite everything aforementioned. This is probably the biggest reason they were successful, and probably one of the reasons Cobain hated his success. He was able to wrap his angst and rough-edged, emotional outbursts in a nice, listenable candy shell that made it extremely popular with his fans. He probably could have made it even more poppy, if he wanted to. The problem was, it tended to make people assume the band was candy all the way through. So the people who liked Lithium came to shows and were utterly perturbed by songs like Milk It. Hey, at least they bothered.
http://www.monitordown.com/2009/08/19/so-you-think-nirvana-sucks/
playstation 3 : 72-74 million 
