I too never take Green Day seriously. To try to label themselves as "punk" is ridiculous. Their "American Idiot" is nothing but bubblegum fake punk-pop. I really hate that song. Nothing that would ever compare to what punk really was, anarchy, distortion, non-conformity. Real punk is not Green Day. I really do NOT like all the posers these days who pretend to be punk. And I know punk is an acquired taste that many people don't like. Basically, if a song is "punk" and mainstream society likes it- it is most likely NOT real punk.
Still, they are a step up above most of today's poison music like Psy and his disgusting music videos and Justin Bieber. Or the stupid "Call me maybe song", Taylor Swift songs. Today's music has no depth. The lyrics are about making money, being conformist, commercial and about the arrogance of being being too drugged and young to care. Music today has not been an "art" for a long time.