Which might be due to a greater acceptance of 2D games on these systems due to their lower processing power maybe?
The Japanese are just not interested in (I would say) overly-detailed 3D HD graphics. They're also at odds with open-world games, which a lot of people in the West adore. They want a pre-determined path, with enough interesting stuff from beginning to end. In the end, even open-world games are limited. I guess Japanese people have seen straight through that illusion of limitlessness... Like I said Japan still makes the best games IMO...