Nearly everyone responds positively to this new alter-ego, which fuels his self-hating dementia to a point where he ends up taking actions that are exactly the opposite of what he ever wanted to do.
In the end, he grows to hate the false persona he’s created that everyone loves, and it is only by both figuratively and literally cutting it away from himself that he is able to realize that his family loves him not for any accomplishment or for the entertainment value he provides, but for who he is—even despite the fact that he is truly very sick. It is a message nuanced by the fact that Black’s wife, played by Jodie Foster, is not willing to merely accept Walter’s disturbed behavior indefinitely. But although she does call him on it, for her own protection and the protection of her children, there is never any doubt that it is love that prompts her action.
The Beaver is not a perfect film, but it is quite a lovely, effective one. I would venture to guess that its poor box-office showing has less to do with its relative merits and more to do with the fact that the average American is not particularly interested in extending to Gibson the sort of love of which Foster has been an exemplar.
Screenwriter Kyle Killen has said that a recurring theme in his work is how much people can change, and that The Beaver is an attempt to flesh out the idea that what we are really stuck with is just learning how to love—both ourselves and others. I, for one, am glad of the reminder, and wish both Foster and Gibson the best.