Former Dixie Chicks' fans were not average movie goers. Instead, they were very patriotic Americans, usually to the right of many Freepers.
It really hurt to have my favorite country group spouting anti-American propaganda in foreign soil as a cheap schtick.
When this broke, a FReeper posted a story about Michael Jordan not participating in some political demonstration/movement a few years ago when he was at the height (no pun intended) of his NIKE shoe endorsements. When asked about why he was abstaining from the whole thing, his pithy reply was, "Republicans wear shoes too."
The Dixie Chicks found out that criticizing your President on foreign soil during time of war, surprisingly, dosen't go over well with the NASCAR crowd.