You Can't Always Be Torn In Two: Sam Gamgee's Two Front Doors

At the very end of Peter Jackson's adaptation of Return of the King, he makes one little change that I've been pondering: instead of returning to Bag End where he and his family now live, Sam returns to his own house. Why?

( I think it has a lot to do with presence or absence of the Scouring of the Shire, and the different ways the book and movie approach coming home after a war because of it. )