It's my belief that he did for many of the same reasons Europe puts up with Iran. We needed the oil. The Saudis may have given the hijackers money to pacify other threats figuring that they would never be able to pull it off. But they did. That's what happens when you try and play both sides. Sometimes it comes back to bite you.
The Saudi leadership clearly does not share the anti-Western beliefs of the Wahhabi sect. The leadership’s beliefs are the minority in their own country.
They are in a tough situation, in that. They have to at least keep a working understanding with the Wahhabists.
I would hate to see the Wahhabi sect become the leadership of Saudi Arabia.
It would affect a number of nations in the region in short order.