In the book, while Frodo and the Fellowship were on their quest, the Shire was exploited and almost ruined by Saruman and his cronies. Jackson left this and the triumphant return of Frodo, Sam, and the now burly Merry and Pippin and their battle to reclaim the Shire out of the film. I was hoping to see it added to the extended version of the DVD, but it was not.

Did Peter Jackson explain why he omitted this portion of the book from the movie? If so, what was the reason?