Writer-Director James Grey on the importance of asking why something happens to characters in film.

You are always in a struggle to avoid cliche; however, it's very relevant to embrace archetype. Some people go to movies for different reasons. It doesn't mean the reason is worse or the reason is better - but people go to movies for different reasons and some people go to see films for the thrill of the whodunnit.

So the dramatic tension for them is the unfolding of events; they don't know what will happen next, and the whole joy of the experience is the unpredictability of the story. I must say that this is not important to me, which is something that is probably obvious to viewers of the film. It's not important to me, necessarily, that the film is predictable or unpredictable. In fact, I almost prefer the film to be inevitable, that the unfolding of events in the film proves itself to be something you could have predicted would happen. And in fact, I think that this view of cinema is born out of an entire history of storytelling, because it enables you to get out of the way of the surprise. So what do I mean? If you look at a story like Macbeth, for example, the witches more or less tell you at the beginning what will happen, so that the pleasure of the experience becomes not what will happen, but why it has happened.

I think if the joy of the experience is what will happen, it becomes a picture or piece of art with a limited shelf life. That is to say, you watch it once and you find out what the answer is, and then you can't watch it anymore. It becomes an irrelevancy. If the question of the film, or the question of the work of art, is why it's happened, then it never ceases to be interesting, one hopes, it never ceases to be about the lives of the people in it. And that, for me, is a higher calling for any creative work. (link from David Lowery's Drifting)