Whats so bad about what the Dixie Chicks said?

All they did was criticize the Iraq war and the lunatic behind it, whats so bad about that? Green day sings songs with lyrics like "The subliminal mind fu*k America!!" and no one cares. I mean the Iraq war was the biggest joke ever and seeing as they never found any WMDs I think they were right and everyone should apologize to them,