[Jourin]

Whether something is a bug or a feature is based off the rule of unintended consequences. You design something that results in an unintended consequence. If that consequence is positive, it is a feature. However, if that consequence is negative, it is a bug.

Using a specific example: Drones were designed with no "move to" capability resulting in the unintended consequence that drones can not do recon. Since I think that the majority of people believe this consequence is negative, this consequence is a bug.

Yes, drones were designed with no "move to" capability, but that does not mean the design didn't cause a bug.

Bugs can be caused by
Sloppy keystroke entry (syntax)
Poor programming design (logic)
Poor concept design (unintended consequences)