In "The Most Dangerous Game", why does Rainford deny the existence of feeling in the animals he hunts?

As he proves himself at the end of "The Most Dangerous Game," Rainsford is a true predator--"I am still a beast at bay" he tells Zaroff.  Then, the last line of the narrative confirms his enjoyment of his having finished off General Zaroff:  "He had never slept in a better bed, Rainsford decided." 

The "most dangerous game" has taught Rainsford much about himself.  In the exposition he does not concern himself with whether a jaquar feels pain, telling Whitney who poses this thought, "Bah!  They've no understanding."  What predator does care about the feelings of his prey?  Rainsford continues, "Be a realist.  The world is made up of two classes--the hunters and the huntees." Clearly, at the story's end, Rainsford expresses his pleasure at being the hunter.  He decides this is what he is.