Several comments here I want to respond to, so in order:
@alexpnz I agree totally
@ApolloBalboa and @DP_LOVER Could not disagree more with your assessment of him as a weak musician. This is a mistake even some trained musicians and guitar players make, but it's absolutely untrue. A lot of people who don't play, or average players think the measure of a musicians skills is technical prowess, playing lots of notes fast, playing complex passages, etc., but that kind of thing is really a measure of advancing from beginner to above average player. The toughest skill to master is learning to play the simple stuff with such compelling sound that people are forced to listen. Cobain was a master of his craft, and a close listen shows he had an exceptionally gifted ear and was in complete control of his instrument at all times. Controlling the feedback and harmonics he created at the level he did it is a rare skill, and I say in all seriousness he was one of the greatest performing guitarists I ever heard, at least when he was playing sober enough to hold it together.
@squallumz I would not be too quick to assume Cobain would hate to be on guitar hero. He had a lot of conflicts with fame, and being seen as a mass appeal guy, but he wrote Nevermind with the intention of creating a commercially successful pop album, and modeled some of the sound of the album on the Smithereens, a band he admired for maintaining a rootsy alternative feel while getting MTV and Top40 play. Listen to "A Girl like You" and a Nirvana song back to back sometime, there's a definite connection there.
@zell Nirvana was doing some of the things the Pixies were doing, but the Pixies were not doing one thing Nirvana was, which is selling tons of records. Cobain had a gift for writing catchy melodies, and while many despise that pop sensibility people in the music industry are painfully aware that writing great hooks is both the rarest and most bankable talent there is. Lots of bands out there with amazing chops that never take off because they can't write singles, for years the Pixies were one of them. And yeah, I know the Pixies have sold some albums, mainly after Grunge led the way for that style of band to get noticed, but they aren't popular in the Nirvana sense, not nearly so.
@lurkingdirk Not liking the Beatles is one thing, but calling them mediocre? Now that's just absurd.