Can't be expected to deprogram their hunting instinct quickly, so throw 'em into a simulation. Makes sense, if not for the live/brainwashed "prey" being used. He certainly planned to do away with living subjects once they had the holodeck tech themselves.
This is perfect timing, I was just watching Quinton Reviews' video on the "downfall" of the History Channel. Highly recommend the video, dude's great at media analysis.