Star Wars = Western
Xbox > GC sales especially in US
And Star Wars games didn't sell to hot other than the orginal SW Rogue Leader, the sequel bombed Rogue Strike along with the others like Clone Wars, Bounty Hunter, and Jedi Knight II: Jedi Outcast.
Other lucasarts games that bombed--Gladius.
Just like everyother 3d party developer, lucasarts dropped gamecube support because of the overall sales.