Most AQ/Taliban scumbags subscribe to the the "inshallah" ("if Allah wills it, it will happen") school of marksmanship. That, and a lot of the foreign fighters are completely hopped up on speed in their preparation for meeting US forces in battle.
The only downside to this is that Darwin comes into play and we eventually have to deal with the smarter ones.
May we mercilessly kill Every. Last. One.
Like Spray and pray, and it is the Will of Allah that they take massive casualties.