Personally, I think it was because Bush was far too concerned about the Libbos whining about being too hard on the enemy. I think that he should have placed restrictions on the press, went in and did what had to be done.
And as far as politicians go, they gave Bush everything he wanted.
The reason these "wars" aren't won, is because there are no armies to defeat.
Al Quaida, like terrorism, can move from country to country and we need to focus on intelligence, international cooperation, and yes, police work in eliminating it, not invading and nationbuilding.