If that were true, then why does the Pakistani government allow it? The drones, as was recently revealed, operated from a Pakistani military base.
Because the Pakistani government and its military understand that allowing the drone attacks represents a critical element of its relationship with the U.S., especially the CIA and the U.S. military. For now the government is willing to take the hit that its public image suffers because of the drone strikes, knowing that the far greater damage is to the U.S.' reputation inside Pakistan, which could actually come in handy for itself in the future.