The author wants to communicate the distinctive personality of the narrator.
Explanation:
A narrative refers to a story or an account of connected events. A closed narrative style is related to the the developement of the narrator's mental and moral qualities throughout the story. Therefore, it deals with the narrator's emotions and thoughts.
The author does not want the narrator's personality to interfere with the story.
Explanation:
The author's main objective is to develop a whole story from the begining to the end. The focus is on the events which may be unfolded through a long period of time. The narrator will try to be objective since the story is more important than the narrator's emotions.