In short, there is nothing tribal about the Taliban, because by the time they emerged so much of the normal tribal and community relationships and rivalries that would ordinarily underpin society had been destroyed. Even the “original” Taliban, had a variety of both Ghilzais and Durranis in its leadership.
The neo-Taliban might have been different, except that as Antonio Giustozzi has documented in Koran, Kalashnikov, and Laptop, there was still a variety of Ghilzai and Durrani (and others) in the Rabbani Shura’s membership. In fact, Karzai’s tribe the Durrani are over-represented, and make up a slim majority of the Taliban’s current leadership. Furthermore, the neo-Taliban’s recruitment strategies are based on Pashtun nationalism and pan-Islamism, not any kind of tribal pleas.
This has enormous implications. Previous governments in the region were able to “rule” the Pashtuns by exploiting tribal divisions, whether undermining individual leaders by exacerbating tribal division or simply by enacting rules that hold tribal leaders responsible for their community’s actions.
The current structure of the Taliban, as a de-tribalised insurgency, means that the usual methods of working within the tribal system are far less effective, if at all. This is why the reconciliation effort has stalled—it just doesn’t apply. Since the Taliban is a movement that is inclusive of traditionally rivalrous tribes, even some rivalrous ethnicities, that rivalry cannot be exploited to undo the movement.