I think I have figured out why contemporary classical music doesn’t satisfy. There are several ways to create and resolve musical tension. There are rhythmical ways, harmonic ways, dynamic ways, timbrel ways, and more. However, of these various ways, the harmonic way is the most easily recognizable way. It works by creating harmonic tension and then relieving that tension. In much modern classical music, there is no harmonic resolution. Therefore you cannot tell when the musical plot has been resolved. Maybe you’ve noticed that when some of these pieces end, you don’t know when to clap. This is because many modern pieces have rejected the tonal system altogether. Without a tonal system, there is no such as resolution. Harmonic musical arcs proceed from tonal consonance to tonal dissonance, and then back to consonance for the resolution.
This idea can be applied to much modern novel-writing as well, especially the more stream-of-consciousness models. If there is no narrative arc from happiness to crisis to happiness, then readers will not be very happy. Of course, that will be the author’s intention in a tragedy, though even there, a resolution to the tension still takes place, just not the one we “want.”
Why do we love this narrative arc? I would suggest that it is because that is how we want history to flow, in its ultimate proportions. It is the narrative arc of the Bible (creation, Fall, Redemption, Consummation). I think God put that arc in all of us, and that’s how we want the story to end.