I agree so much with what you said about many many songs being a "stage wait" and that isn't always a bad thing. But I also agree that you are asking something different of the audience in a film than a live show. The example I keep coming back to is Les Miserables. I love that show on stage. Seeing the movie made me realize that most of the songs are a person alone on stage singing about how they feel. I thought this was deadly on film, especially with the static filming and the camera lens up the actor's noses. Because of the staging and the (unspoken) understanding between live audience and performer, it never once occurred to me that the songs were not loaded with action.