The movie is presented in its theatrical aspect ratio -- i.e., the dimensions that it was made in for movie theater screens. In order to make it "fill" a television screen, they would either have to stretch it vertically, which would result in a distorted image, or they would have to crop out the sides of the image to make it match the size of the television screen (meaning that you'd lose part of the picture). Do you *really* want them to do either of those things?
Ummm really? I am still blown away when people don't have a clue about aspect ratios of movies. It is a 2:35 movie, not a 1:85 movie ( the shape of you HDTV) so it is going to have black bars on the top of the screen. They kept the aspect ratio of the theater presentation. Just use the zoom on your TV it will get rid of the black bars on the top and bottom.