Actually, I think that the scene in Ellis Island serves a definite purpose. It was there to portray how the immigrants were treated when they arrived here, and that typically American impatience with anything foreign. The same can be said for Geary's purposeful mispronunciation of the Corleone name during the check presentation. It may even have served as FFC's dig at non-Italians for their treatment of Italians. As a second-generation American, I'm sure his grandparents had shared stories.