This is true. Kurt Cobain was a crap musician (though he did have a unique voice). Anyone with a few months of guitar experience could play all his songs with their eyes closed. Heck, how did someone like Britney Spears get popular? At one point she was the single most recognized name in the country! And she can't even sing. Here's the unfortunate truth. Music is NOT a meritocracy. Far from it. Labels find or build a band. They choose what the public will like next and they pay off radio stations to play the songs and TV stations to play the videos and people just eat it up. The exposure makes the band famous and they are popular even if they never had any real talent to begin with. To be fair, Green Day is far from being the worst band ever. At very least they write catchy songs and that takes some ability to do. Yet anyone who doesn't like them has plenty of ammo on their side. Get used to the fact that, in general, there aren't many good musicians in punk or pop punk. Drummers, maybe, but that's about it. Green Day is a below-average group that just happened to strike it lucky.