The Taliban were beyond brutal, to women, children, and Afghans from the other ethnic groups (Tajiks, Uzbeks, and - above all - Hazaras) who weren't Pashtun. From what I could see, they were fanatical Pashtun nationalists - conflating this (and a ferocious interpretation of Islam) with Afghan identity.And Afghanistan was not the target.
The target were the Taliban (which held power on almost all Afghanistan; and they were brutal on Afghans, especially women and children), and Al Qaida members that were in Afghanistan, protected by the Taliban. The Afghan war was - I repeat - different than the other wars specifically because of 1) 9/11 2) the power structure in Afghanistan (a mix of state and tribal actors). The taliban still control lots, if not most, of the power and regions in Afghanistan although it seems that they chilled out a bit from an international terrorism point of view.
However, while I was delighted to see them overthrown, they weren't responsible for the events of September 2001, other than (foolishly bound by their own extravagant traditions of hospitality) by granting AQ sanctuary.
The Taliban were never international terrorists (now, granted, I'll readily concede that they were domestic terrorists); they lacked the vision, resources, and motivation.
Of course, AQ was very different.