Moderate Taliban is an oxymoron. Its like the moderate Chechen President who managed to temporarily mollify the restive province by endorsing honor killings & forced veilings. Knowing the Talibans' beliefs, their ideas of "moderate" are likely to be more extremist, not less. Maybe, just maybe they'll refrain from attacking U.S. Troops but they're likely to have medieval attitudes towards criminals, women & dissenters to name but a few. The potential threat these "moderates" pose to those who disagree with them far overshadow any potential benefit of sucking up to them & earning their goodwill.
http://www.bloomberg.com/apps/news?pid=20601087&sid=aYO0kXhIuplkThe U.N. should rename itself, "United Islamist Ass- lickers Association."

This is how foreign policy works. It's not based on principle, it's based on perceived self-interest, usually with less consideration given to what the results will be 30 years down the road, than to what will happen within the next 10. US foreign policy is the whole reason the Taliban got into power in the first place, so this should not come as a surprise.