I agree that movies and television programming tends to be more shallow than books, but this has more to do with how they are produced than it has to do with their potential. Video has the potential to demonstrate ideas through motion and sound in a way that would be difficult (if not impossible) to do through the printed word. It can also replace the written word with the spoken word.

Of course, it rarely does so. I suspect that this has everything to do with production costs. Higher production costs means that you're liable to create a product that is shorter and that targets a broader demographic. That kinda kills off the notion of depth.