If anything I would say Nintendo should. Their ip franchises are very mainstream and if they were multi they would be making even more crazy loads of cash on those games like Mario Kart, Mario & Donkey Kong. Leave the console making to Microsoft & Sony.
How our favorite systems are just like humans and sometimes have issues finding their special someone...
Xbox 360 wants to Kinect & PS3 wants to Move! Why are both systems having such relationship problems? The reason is they both become so infactuated with desire while watching the Wii as it waggles on by. They simply want what they can't have.