Hey, watch it now!
This is an argument that can easily go both ways. Yes, U2 is a European band....as were The Beatles, as were The Stones, Pink Floyd, etc. But it wasn't until they all came to America that they made it big.
Yes, some Americans are dicks and ruin our image for the rest of the world. Thankfully one very powerful dumbass just lost his 8 year job and is moving back to his ranch in Texas
But to disregard the importance of making it in America when it comes to music would be naive. This is where almost all of the major movie and music companies reside. This is where the largest radio and television markets are. You can't deny that...no matter how dumb some of us are.
Every band knows that....especially European bands. You know there's a joke about bands "who are big in Europe" and its not flattering. Basically it states that "anyone can be big in Europe". Now we know thats not true, but regardless of that fact to deny the importance of making it America would be to deny a band success.
Plain and simple: If you can be big in America, you'll be big EVERYWHERE.