The Taliban are religious bigots who imposed and would impose again an extreme form of Islam. While the resistance to their efforts may not have the same dynamic as the Sunni Shia divide in Iraq, it is hard to get away from the religious aspects of their efforts. They are murdering barbers and attacking people who shave based on some weird reading of the Koran. They are destroying schools that teach women, because of some weird religious belief. The government forces resisting them have a different take on what Islam requires, so I think it is fair to say it is a sectarian civil war.