In his Carnegie Medal acceptance speech, Philip Pullman states: “There are some themes, some subjects, too large for adult fiction; they can only be dealt with adequately in a children’s book. The reason for that is that in adult literary fiction, stories

In his Carnegie Medal acceptance speech, Philip Pullman states: “There are some themes, some subjects, too large for adult fiction; they can only be dealt with adequately in a children’s book. The reason for that is that in adult literary fiction, stories are there on sufferance. Other things are felt to be more important: technique, style, literary knowingness.”
Explain this quotation and highlight its significance to Philip Pullman’s novel Northern Lights.