Film is the manipulative medium par excellence. When you think back on the history of film and the 20th century you see the propaganda that's been made. So there are moral demands on the director to treat the spectators as seriously as he or she takes himself and not to see them merely as victims that can be manipulated to whatever ends they have.
If you are going to have to play defense all the time you cannot have the kind of ingenuity assertiveness independence and intelligence which is what has made our country strong.