For about the same reason, Sarkozy must be seething that Ingrid Betancourt was freed and that he can't claim credit for it.
Eli Sagan, in his excellent book THE HONEY AND THE HEMLOCK-Democracy and Paranoia in Ancient Athens and Modern America, notes that we, as a species, have so many psychological debilities that it is a wonder we can even live together in complex societies as well as we can. Especially true in the USA. As the Dutch said while fighting the Spanish: "It is not necessary to have hope in order to persevere."
Personally, I doubt the attack would have occurred with Gore in the White House.
Bush accelerated the fall of America by a century. What would likely have been a gradual decline has been compressed into 7 brief years. It was a win-win situation for Bush and bin Laden. Bush and his base got rich and bin Laden and his base got America to implode.