Why Green Day Are Not Sellouts
Let me start by saying that I am a greenday fan. I enjoy all of their music, right from 1039 to the 2012 trilogy. However at the same time I am not a fanboy, I feel that my opinion that green day are not sellouts is made from rational reason arguments, rather than "Green day are the best brahh".
"They're not punk"
It frustrates me when people insult my taste in music or the band by saying "Green Day aren't punk". Firstly I'm not even sure whether Green Day themselves would like to be "punk", punkrock maybe, similar to bands that inspired them such as The Ramones.
The statement also annoys me due to how I define punk, the aim of punk is simply to do what you want to do without caring about what others think. Green Day in their early days especially did this, less so now however that brings me to my next point.
People Grow up and change
Often a reason that is stated on how Green Day have "Sold out" is that they are no longer as they were at the time of Kerplunk and Dookie. Their music is no longer as raw and they don't perform their sets off their face on drugs.
In the early 90's Green Day were young (age 22 in 1994) and thus were physically healthier and more resilient, they also had no family responsibilities, This means that they could do mental tours where they would get high almost every day and live that lifestyle. Being young also effected their thoughts when songwriting. Most of Green Days early (Pre insomniac) songs are about themselves, ranging from girlfriends/loves and crushes (Judges Daughter, 2000 light years away) to their environment (Christie Road,Longview), to their lives (Welcome to Paradise, Coming Clean). Most having a similar classic punk rock style of loud, fast and angry.
However as the members of Green Days lives changed then so did their music, this has to be expected. Insomniac is the first album to have a number of reflective songs, Green Day had become successful and Billie Joe Armstrong had just had his first child, his life was changing so his music did too.
Since then as they have grown older (42 in 2014) and thus have more responsiblities in life (both family and financially) their lyric topics have changed from being about themselves to about others and telling stories about others. This is most obvious in American Idiot and 21st Century Breakdown albums which have repeating characters throughout.
I personally like all of Green Days styles and listen to different albums depending on the mood I'm in. I can understand people not liking certain styles of their music, however its unfair to act as if Green Day should still be the same band they were more than 20 years ago. That is unrealistic and unfair to criticize.
Do you Prefer old or new Green Day (Before or after 2000)
They are also musicians not just Green Day members
This is specifically true for Billie Joe Armstrong guitarist and songwriter (the other members are too, however Billie is the most obvious and largest influencer of Green Days songs). Billie Joe is involved in many other sideprojects alongside Green Day, such as the separate band Pinhead Gunpowder, other bands with Green Day members (Foxboro Hotubs and The Network) and appearances with other artists such as Foreverly with Norah Jones. if you look at his instagram he is often posting pictures about other artists as well.
I have heard people say that Green Day are sellouts because of all of these other projects and how it is simply to make more money. However in reality Billie Joe Armstrong just loves music, including other styles that Green Day aren't and thus persues them elsewhere.
American Idiot Rock Opera Sellout
The most common reason I hear is that Green Day are sellouts because they made a broadway musical, arguing that there is no better way to cash in on their success.
However I would combine this partially with the above paragraph. The musical/rock opera was an opportunity to explore a slightly different (but similar) art form. The musical wasn't a spur of the moment idea, it was something they had been thinking about for a long time, and for proof skip to 3:13 in this interview taken in 1993 where they mention a Rock Opera called Jimmy.