Mise en scène and production costs
The mise en scène style is associated with the auteur theory of film making: A director’s films reflect a personal creative vision, as if the director were the primary auteur, French for “author.„ Major films are made using an industrial process, but a director who is allowed a high degree of creative control can produce a film with a distinctive voice.
If a long take is involved, careful planning is required to make sure that actors and camera — and often the special effects — are synchronized.
In a long take, actors must act. A performance cannot be saved by cutting away. If a mistake is made, the entire shot has to be taken again. The economics of Hollywood production frown on such methods, but directors know that long takes seem more realistic. In this video, listen to Alfonso Cuaron describe everything that went into one particularly vivid scene in Children of Men (2007), then watch a larger version of the scene.