Note: there's two semi-distinct groups, the Pakistani Taliban and the Afghanistan Taliban. A Pakistani farmer-serf is unlikely to agree with the Taliban on spiritual matters: most rural Pakistanis are Sufists, they worship local saints. The Taliban are hard-line Wahhabi fundamentalists, they consider Sufists to be idol-worshipers. A cultural revolution, like the ones in Afghanistan and Iran, is unlikely in Pakistan.

The Pakistan Taliban has a pretty good reputation in the Pashtun regions. ("Taliban" is a pashtun word) One of the more popular proposed reforms is Sharia law.

Sharia has an appeal that's difficult to understand in the West. Pakistan's official court system is deeply, deeply compromised. The police are hopelessly corrupt. Cases take many years to resolve, and victory goes to the person who paid out the most in bribes.

You can use the parallel legal "system", jirga tribal law. Jirga is less "legal system" and more "binding arbitration". It evolved to end blood feuds by negotiating settlements between tribes, and as such, can be blindingly unfair.

Compared to these two equally terrible alternatives, Sharia looks pretty good. In fact, Muhammed invented it back in ~600CE precisely to stamp out customary law. Compared to jirga, it's positively progressive, esp. in regards to women. (Which makes sense, it's about a thousand years newer than tribal law) (Many interpretations of Sharia allow women to own property, for instance; and Islamic judges typically don't settle blood feuds by trading women)

EDIT: Ha ha, remembered the wrong date.