Definition and terminology 
 To distinguish UAVs from missiles, a UAV is defined as a "powered, aerial vehicle that does not carry a human operator, uses aerodynamic forces to provide vehicle lift, can fly autonomously or be piloted remotely, can be expendable or recoverable, and can carry a lethal or nonlethal payload".[6]  

 Therefore, cruise missiles are not considered UAVs because, like many other guided missiles, the vehicle itself is a weapon that is not reused, even though it is also unmanned and in some cases remotely guided.  
     
 The second sentence makes no sense following the first:  "... cruise missiles are not considered UAVs because the vehicle itself is a weapon" but UAVs "can carry a lethal ... payload" and "not reused" but UAVs "can be expendable."    

 I would think one would simply say cruise missiles aren't considered UAVs because of their (hopefully) rarely used narrow mission profile and to prevent any ambiguity between this mission and common UAV missions.