The style of answers is incredibly different. I won't give my opinions on literature, but they prefer to use analytical techniques to reach their own conclusions based on supporting evidence from the texts, and the questions on the site reflect that kind of analysis.
On SFF we prefer what users call "WoG" answers. Effectively they answer the question by a statement made by the creator of the work in one of his works, this can take various forms. Answers sometimes to do some extent use analytical techniques, but most users don't have the "necessary skills" to carry out an extensive analysis.