And your point would be? oh and no they d not serve the same God. Christian and Jew Maybe but not muslim. They all three might serve a one figure God but they are not the same.
But your point does not negate the fact that 9/11 was done in the name of religion.
While it may have been claimed to be in the name of religion, 9/11 and the Crusades were both actually done for the benefit of someone crafty enough to convince a bunch of idiots that they were doing God's bidding. In the end, both were done in pursuit of power for some person.
Bin Laden in not a Muslim purist, he's using religion as a means to acquire power. He got all butthurt when King Fahd wouldn't let him lead the defense of Saudi Arabia alone. While this is a gross oversimplification, the current war against the US is an attempt by Bin Laden to show that he can beat us. At that point he then (in his view, IMO) will have credibility to take over Saudi Arabia and install the first modern Caliph (leader and uniter of all Muslims).
It's a power play, that's all. Islam in the areas where Bin Laden and his associates attain recruits is more cultural than religious.