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.
I had a roommate once who would turn on the Nazi ... I mean The History Channel on every night to fall asleep to, so I would come home to 365 days of Nazi tv, which was upsetting. He couldn't see the problem. I found another place to live.
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.