Working with Afghan organizations I've learned that allied/U.S. air strikes killing civilians and U.S. support of Hamid Karzai are the two issues that anger Afghans the most. This is a personal-experience diary; there is much written that reflects what I've heard.
Most Afghans I have talked to want the U.S. and its allies out of their country. They consider U.S. involvement to be the main reason for whatever strength the Taliban has, and U.S. withdrawal would weaken it as well as give the majority of Afghans the opening to oppose it themselves in a number of ways.