The funny thing is Green Day and Operation Ivy were the epitome of punk when they started. They played all ages shows in Berkeley where anyone from middleschool kids to college students could come and listen to some hard charged fast ramones style punk music, and in the spirit of late 70s punk, pop pills, drink, and just cause havoc. Obviously music companies are out to make money and they jumped on the burgeoning 'punk' scene, yet you can't play songs like 'too drunk to fuck' on the mainstream radio, so they see these nice young mainstream friendly punks they could exploit. and if you are in a band, your purpose is to make the kind of music you want and for people to hear it, so if a record company says we'll pay you a lot of money and get you a lot of exposure and you can help other bands like yourselves 'make it' it's hard to say no. I don't know the whole story but Op Ivy probably saw this happening and didn't want to taint their underground name and place in history, so they formed Rancid. Just because music is popular doesn't mean it sucks, but most Green Day sucks now, but part of that is because it's a waterdowned version of what they used to be. The Dead Kennedy's guy knows the right bands, but you've got to include Bad Religion, Circle Jerks, X from the LA scene and Television, Richard Hell, Johnny Thunders and the guys from the NY scene.
A side note, supposedly in the early 80's the dead kennedy's played at my high school, but the name was considered offensive so it was billed as the Pink Twinkees.