"The Hole" and "Amusement" display clear background stories and reason within the plot that have been gradually explained throughout the films, relying heavily on the psychological elements to appeal to the audiences' want of a complex storyline and the freedom to draw their own conclusions about the mental health, emotions and justifications of the characters' actions and reactions.
By providing motives for the protagonists, they are no longer ruthless killers in the eyes of the audience, but troubled people. Often, plots such as this cause the audience to try to understand and even favour the killer at one point or another, or at least feel sympathy for them.
By letting the audience into the minds of the main characters, they can often relate to them somehow, and will feel their feelings with them. A plot such as "The Devil's Rejects" also allows this, but relying heavily on the sexual and violent aspects of the film has slightly numbered the effects on the audience reaction, and instead we root for the antagonist. Some may look at the "senseless killing spree" based films as cliché and bland, however if made correctly can sometimes match films with a deeper "original" plot.
