The architects of the COIN nonsense seem to be engaged in some WWII nostalgia. During that war when allied troops marched into liberated cities the citizens were jubilant and loved their liberators. In Afghanistan the general population does not view themselves as needing to be liberated. First and foremost they view themselves as Muslims and they view the allied troops not as liberators but simply as infidels.
Our troops could stay bogged down in that wretched hellhole for a hundred years and they will never receive hugs and flowers from flag waving grateful people lining the streets. They are more likely to receive a bullet in the back.