Personally, I don't like the term 'success.' It's too arbitrary and too relative a thing. It's usually someone else's definition, not yours.
I heard that in the United States the level of baseball was the highest in the world. So it was only natural that I would want to go there, as a baseball player.
The more that Japanese players go to the big leagues to play and succeed, the more that will serve to inspire young kids in Japan to want to become baseball players when they grow up.