Because they're really known for working out the kinks before they open things to the public...?
My theory is that Japan will not let most of the recent issues happen as a matter of cultural pride and then the operation will be carbon copied with a few cut corners here in the states.
Virtual Queue won't work in Japan. You guys were complaining about the waits here for Volcano bay, Osaka waits without express can get up to 600 minutes for some things (has happened multiple times). They would have to virtual queue the entire land and not just the area.