There's a great deal of that in his other fatwas. I think bin Laden also mentioned taking revenge for the bombings of Hiroshima and Nagasaki, not to mention the Crusades (which did not become a big Muslim issue - since the Muslims crushed the Crusaders and pushed Christianity back from the Holy Lands well into the Balkans - until leftists started making a big deal of it in the 20th century). A lot of bin Laden's screeds are just recycled leftist pap. Bin Laden hates us because he views Muslim governments as puppets on American strings, meaning that our capitulation would simultaneously deliver these governments into his hands. As long as these governments don't answer to him, he will keep on attacking us. But when he gets control of them, he will leverage them to launch even more ferocious attacks. Look what happened in Afghanistan - the Taliban became little more than al Qaeda's Praetorian Guard.
Is he a fantasist? No, he's a master propagandist - using leftist rhetoric is how he got Washington state's Patti Murray to say good things about jihadists. If he confined himself to rhetoric, everyone could just ignore him. His attacks are unfortunately, all too real.