Famitsu: Wii has the highest attach ratio of any console since 96' in Japan

[DKII]

Controllers are accessories and I bet more people have 4 Wiimotes than 4 Sixaxis or 360 controllers by far. PS3 and 360 only really focus on online multiplayer so you don't need 4 controllers, most of them have 2 if not 1 I bet.