Hadmid Karzai (not my favorite Afghan) has pointed out what should be obvious, the civilian contractors in Afghanistan are are seeking profit at whatever cost to the Afghan people.
"Contractor" in Afghanistan and Iraq is just a polite term for "mercenary." They are not there to be nice or kind or helpful or even loyal to a cause. They are there for money and money alone. They have a vested interest in insuring the war lasts forever (there is no profit in peace).
If they can double their profits by working with the Americans during the day and helping the Taliban at night then they will do so without the slightest qualm. Are civilian contractors providing security for opium druglords? Almost certainly, and they are probably double billing the United States Army for the work.