The problem with fact is that it is so concrete. It's very black and white. This happened. It happened at this time, with these people, at that location. The facts might be detailing events of something great or something tragic, but the factual details almost always fail to arouse any sort of emotional response out of a reader.
I've read about feudalism a lot. There's always talk about dark ages and castles and these people called serfs. It's just a bunch of dates and vocabulary terms to me. I have no real thoughts and emotions about it. I felt the same way about the Great Depression until I read "Of Mice and Men." After that I understood how awful that time period must have been to a lot of Americans.
I've never been to the deep south, so all of the factual information about race relations and small town life never really made much of an impact on me. But while I was reading "To Kill a Mockingbird," I found myself genuinely upset that Atticus lost the court case. I was mad that a community could be so blinded to the truth because of a skin color.
As for "Catcher in the Rye" . . . I know that there are all kinds of different people out there. That's a fact. I know that different people have different attitudes about a lot of different topics. That's why I never bring up politics at family get togethers. And I know that there are times when I just don't understand where a person is coming from. People like Holden, I don't get. But reading about Holden helps me empathize better.
That's what fiction does better than fact. It provides an emotional context to tie the logical facts to. Fiction can give a clearer picture of an event, time period, person than fact because fiction triggers emotional and logical centers of the brain.