Why is the world suprised?! Why were millions of people astounded by what happened to Al Quaeda? Did the world think anything else would happen? That something less than this would happen?!
It seems ludicrous to me, a Hollywoodish PR title for a group more akin to a gang than anything else. Imagine this press report from the 20's: "Al Capone's spokesman said today...." Doesn't quite work, does it?
I maintain that terrorist groups are a way for the psycho nut case criminals among us to justify their anti-social behavior. It is not impressive to say you are a criminal. But hey, tag whatever political reason you can muster onto your criminal behavior, and suddenly you are a terrorist and get to have spokesmen and op-ed pieces in the New York Times!