What are we supposed to do? Pick the strongest warlord and give him absolute power? We are trying to build institutions that withstand, transcend and transform the Afghan political and tribal culture. Yes, it's hard, but other alternatives would just end up bringing the Taliban back, and stronger than ever.
Afghan political and tribal culture provided a refuge for Osama & Co. As a result, the place received a cultural and political enema.
Moral: if you want to keep your "political and tribal culture", kill any terrorists who try to use your land as a safe harbor. Bonus points for pickling the heads and mailing them to the White House.