This doesn't mean that fiction is useless for learning about the world. It just means that fiction does not contain the tools necessary to decide if something is true (or accurate, or possible). Fiction may spark an idea or make an argument, but you must go outside of fiction to see if those ideas have merit.
Plus, and this is often ignored today, big pictures are not entirely mutually exclusive. To use a comp sci analogy let's look at search algorithms:
Use cases are more similar to deterministic partial solution searches (backtracking depth first search, breadth first search) for which the more interesting problems are intractable. Additionally, such search algorithms are very self contained, and it is usually quite difficult to combine them, making these algorithms a one time tool.
On the other hand, big pictures are more similar to stochastic solution spaces searches, which won't get you the best solution, but they'll get you a pretty good one much, much more quickly. And since solution space searches all interface with the same space, they can be mixed and matched depending on what is most useful for the problem domain. For example, with genetic algorithms, once you can make your problem domain fit a standard GA representation, the whole of GA theory can be applied.
Aldous Huxley, for instance, both in his fiction and non-fiction, and I see no great gap between them other than the mechanisms employed, has profoundly shaped my thought with his writing.
To top it off, I read because it's fun. Why does everything have to have some Franklinesque color of self-improvement?
That's why my two favorite startup books are High Stakes No Prisoners and Founders at Work.
EDIT: Ok, not all, just the ones in English. ;-)
And a further EDIT: all three of those books are about "Art" more or less. I can't see how someone who read those books can't read fiction. So I'm guessing you missed "only."
nice quip, until followed to its logical conclusion ;-)
One common excuse for fiction reading is to suggest you learn passive facts about the setting as you progress pleasantly through the story, but that's not a particularly strong argument in favor or reading fiction. Sure I could pick up a book about Austen-era England or I could read an Austen novel and get a slightly inferior product education wise with a nice romantic chaser.
That's not what I'm talking about. Specifically I think fiction is a way to learn though experience vicariously, and I think there are some things learned best and perhaps only that way.
For example I could read a terse description of objectivism or I could read a Rand novel and walk a moment in the shoes of her characters. I would argue that the chance of fundamentally understanding what her philosophy is about through channel one is very low, although it takes a lot less time.
Another example: I could say "Sentience is not mutually inclusive or exclusive of understanding" or alternatively read Speaker for the Dead. "Morality resides entirely with intent rather than result" or read Ender's Game. "What is self?" or read Down and Out in the Magic Kingdom.
The deepest and perhaps most important topics can best be addressed this way. Regardless of how you feel about the historical accuracy of the Bible or Qur'an, certainly someone found it valuable to tell stories and parables to covey abstract concepts.