It has nothing to do with guts. It has to do with storyline and purpose. Why would he randomly kill off a main character? If the story comes to a point in which a main character has served their purpose and the story would be enhanced by their death, he may choose to kill that character. If however the story never reaches the point in which the story would be enhanced by the death of a character, then he wont do it. This is his story, not yours