It makes sense to ban recreational use of drones. Like other motorized vehicles, they aren't compatible with wilderness. But I do think they should be permitted for certain uses that could provide great benefit.
SAR: Drones can efficiently cover a much larger area than ground searches, and they are much cheaper, and probably less intrusive, than helicopters.
Scientific Research: Most research is carried out with limited funds, so drones might allow data collection in remote areas or rough terrain that would be otherwise impractical. They might be used to study the effects of air pollution on wilderness, to track damage from pine beetles or recovery after fire.
Law Enforcement: Drones could be helpful for things like detection of illegal marijuana farming in national forests, allowing wider observation with limited personnel.
Of course these uses would need to be regulated in order to minimize disruption, but we shouldn't prevent them without careful consideration.