The irony in this story is that the Taliban historically were against opium production. Some of our allies such as the Northern Alliance (which helped bring down the Taliban), were big producers and you can read about this as far back as 2001: http://www.theguardian.com/world/2001/nov/25/afghanistan.drugstrade
Intelligence is nice, in WWII it let the Germans know that there was a huge invasion in Normandy, or that Stalingrad was surrounded and the 6th Army was about to be swallowed up. Intelligence doesn’t fight the fight for you, and we can only afford and deal with so much at once. The US Army and Marine Corps were already stretched to their limits in 2003 - 2011 committed in the Sinai, Balkans, Korea, Somalia, Sudan, and fighting in Afghanistan, Iraq, and the Philippines (Abu Saeff) all awhile still conducting things like evacuation operations in Liberia, post tsunami assistance etc. While our casualties were in all reality below any threshold of real statistical concern, the burn out on troops deploying repeatedly was real, so were the operational costs, and the political damage. Pushing harder would have required more troops (which we didn’t have) and would have gotten us more casualties, and more political damage.
We live in a world with finite resources. How to best allocate them, matters. Picking a fight with everyone we disagree with in “any aspect,” might not be the smart thing to do.
“in WWII it let the Germans know that there was a huge invasion in Normandy”
They were fed false information on that one, were expecting it in another area.