To understand why people hated Green Day you have to understand Punk culture.
Green Day started on Lookout records, one of the biggest punk labels in California at the time. That whole California skate-punk scene developed around Bad Religion. Punk isn't just a type of music, it's a culture. We put on our own shows, we put out our own records, the whole scene was built around D.I.Y. ethics and radical left wing politics. No ticketmaster, no major labels, no radio and TV coverage. It was all underground, that was a big part of the appeal. The mainstream music industry was seen as the enemy.
Green Day played punk music and they dressed like punks, but that's about as far as it went. Green Day and The Offspring were the first two punk bands from that scene to really make it big, but they didn't represent the punk scene at all.
The when Green Day changed styles and stopped playing punk, many punks got the impression that they just used the punk scene to get big and then chucked it aside when they no longer needed it.
The biggest new punk band currently is G.L.O.S.S. (Girls Living Outside (of) Society's Shit) featuring a trans-gender singer. The biggest punk label Epitaph just offered them a $50k contract (which in underground punk scene is a HUGE amount of money) and they turned it down, because Epitaph is distributed by Atlantic Music (a faceless/heartless major label) Fat Mike then offered them $15k which they also turned down. They decided to release the albums themselves... That's what's expected of Punk bands. My band used to play punk rock, and all the biggest promoters said, no, we don't put on Punk rock shows anymore, we don't want another Green Day on our hands.
Imagine if Brock was the face of MMA, that's a little bit what it was like for the Punks, having Green Day and the Offspring as the biggest voices in the scene was a joke, they didn't even embrace punk culture.
