Whilst most drones are just for intelligence gathering the countries that have the know how arm them so they can be used to kill people or destroy things. America, Israel, UK, France and some others build armed drones because they want the option to kill as well as spy. Whist missiles might get more smarter and not cause as much damage as the current generation of missiles but the way America & Israel use drones for targeted killing today is the future of warfare. More and more countries are going to use these tactics, the real obstacle right now is few countries have the capability to make armed drones right now and countries like America have signed treaties agreeing not to export those thngs to keep that capability in the hands of a few but it won't stay that way forever.
Man shot dead in northern Israel town of Bi'ina, police say the murder was gang related (Haaretz)
from the article: Drones propel hate in Pakistan for the U.S.