Entertainment

I guess it depends on the piece. Is the movie trying to be entertainment or art?

In the end It's a visual medium as well audiotory. And therefor you have a several ways to achieve your message and vision.

From the picturesque to basic exposition throu dialog. Music is another factor that can elevate a movie to new hights.

Both 'Dune' and 'We Need To Talk About Kevin' rely mainly of visual storytelling. But do so in vastly different ways.

But take the typical Steven Spielberg movies from the hight of his career and you can see how much he leans on the music score to achieve his vision.

But it all comes down what type of movie the director wants to make.

Addendum: I will admit that well written characters and dialog isn't as easy to come by in Hollywood media. But movies that mainly focus on the writing and are great do exist.