Thanks for your replies, guys! I see where you are coming from, however I wanted to give my perspective on some of the issues you've mentioned.
So let's turn this question around. What do you personally gain from reading about something that happened that you never personally experienced or felt the impact on beyond a personal gain or new understanding?
If I understand you correctly, there are many ways of answering that question, and answers would vary depending on which specific genre of non-fiction we're talking about. I think all of these answers at the end of the day would have a common theme, the intrinsic value of knowledge. Learning about science or history or philosophy is valuable precisely because these involve mulling over of things that in fact exist or events that in fact took place. For me personally, this concrete ontology is very important, because it can guide our actions in this world in a tangible and robust way.
I get into fiction mainly because I enjoy getting sucked into a world or a different atmosphere; the fact that none of this **** actually happened is completely irrelevant to me.
Let me clarify my stance here bit more. By saying I don't understand fiction, I'm not attempting to take a moral stance which implies the non-fiction reader is somehow better or more stable than the fiction reader. As Esper above mentioned, a work of fiction (more so graphic novels, yet more so games) can be immersive enough to effectively promote suspension of disbelief. At that stage, when you've crossed that line, the concern I raised earlier no longer applies. But my concern was precisely about that mental exercise itself, the idea that when I'm sitting down with a book, I have to momentarily tune off my ontological radar and commit myself to what the author is selling. It's that act of crossing the line itself that I find counterintuitive.
I know once one get started on a fiction, it's super easy to like it. But that's the easy answer to my question. The reason I probably would not include a fiction book in my library (unless one day I want to study literature or something) is because of the very reason that it's immersive enough to fool my senses. It's that I don't understand the point of making that commitment to begin with. Hopefully this makes some sense.
Whether these things actually happened or not is a completely moot point because the way the works are written are capable of inspiring very real change in people.
Well if that's the reason you read fiction, then I would actually understand where you're coming from (although in my case personally I'd resort to non-fiction for that same purpose). If you're studying fiction because of some therapeutic reason (like the one you mentioned), or as a commentary into real world issues (e.g. Voltaire's
Candide or Orwell's
Animal Farm). I admitted to these exceptions in my OP. My question was specifically about those people who choose to read fiction, to commit to a (usually large) novel or even a series thereof, only for the purposes of seeing how the plot develops, or what happens to the characters and so forth. That's the one aspect I have difficulty understanding.