Oh i'm sure he did do it, but as far as i know he didn't create Al-quida (or did he?), and even if he did, if there wasn't an Al-quida there would still have been other terrorist militants.
I am so sure of it because all evidence points to him. Specifically, he admitted to it. He is the head-master of the terrorist organization and the training camps to which the hijackers belonged.
The specific event may have been different but i think you can make a fairly strong case that terrorist action was inevitable.
But fundamentalist predate him, so too does organised fundamentalist terror networks. If the only thing that makes him different is his money, well there are other rich fundamentalists.
Indeed there is a difference, but much more slight than you are letting on. Hitler entranced his nation like no one else at the time could because of his unique personality and Osama is now entrancing probably millions of America-haters like no one else not because of his uniqueness, but because he has the means (namely billions of dollars and a single recognizable face among the people and a world-wide network of well-funded terrorist cells). He is not simply "another rich fundamentalist."
Given the growing anti-American feeling in the Muslim world, it seems inevitable that anti-American terrorist networks would form, and dire consequences result.
Whilst it may well have saved the people who died in the 2 towers on 9/11. Maybe there would have been a 13/02, maybe it would have been a different site. Who knows.
Again, it is true that were we to eliminate him before he planned 9/11 (and even still now) there are others waiting in line behind him to attack us, but my entire point in all this discussion is that it is a profound revelation to exclaim that you think having a different president is more important than saving the 3000+ innocent people who died 2 years ago.
Perhaps a different response after 9/11 could have done much to ease the tensions in the Muslim world, perhaps we are heading towards a nightmare scenario where the terrorists and the Western governments each continually scale up the violence of their responses.
Lots of "perhaps"'s to be sure, but then given the nature of the original question that's all we have.