Because there is something for everyone. Argue that point to him. I feel like tastes is video games often shadow tastes in movies. If he liked fast and the furious, he should look into racing games. If he liked lord of the rings, he should look into fantasy or RPG games. If he liked any number of gun-play action movie first person shooters is the way to go. If he just wants to be creative, theres games like little big planet or maybe even the sims.
I like action and shooter games, so I got a Xbox 360. My g/f likes cutesy non-violent adventure games so she got a Wii. Get a feel for what he likes and then you can make suggestions.