Well, from what I've seen of season 4, (Awakening the Dragon) Bakura is practically all but forgotten, and Yugi, Kaiba and Joey must fight Dartz to save the world. If you watched the first 3 seasons you would understand the 4th. Kaiba is not a team player, he works on his own with little regard for Yugi, although yugi does a damn good job in keeping up with Kaiba as it is. Joey is one of the "good" guys, Bakura has an evil spirit in him and as far as I know he's not in the 4th season at all. Hope this helps to explain what the creators were thinking.
