its just a reaction to amreeka
So you guys are pissed off with the Yanks, so you attack a Shia bus. Makes a lot of sense!!!
Taliban is blowback on the ISI and Pak army who supportes these groups against democratic forces and to intervene in India, Afghanistan and for all short time in the 90s, our establishment had dreams to topple the Mubarak government in Egypt and the Algerian military. The ease by which the Taliban operate is because of the sympathisers that still have among the security forces.