It is fiction, so it isn't a history book and there are plenty of assumptions on how things will work. However, in good fiction, those assumptions are plausible and highlight a future that may happen.
Dismissing fiction is just like having a stock manager that dismisses quarterly reports since they don't definitively tell you how the company will be doing - they just tell you how it has been doing. Prediction and imagination are not flawless tools, but they are helpful to plan for the future. (Which is amusing to say in the light of the book being discussed)
If I similarly just made up a book where police surveillance was the best thing in the world would you cite that as an argument in favour?
How can you use a made up story to argue something when someone else could make up another story that disproves your point and proves theirs?
Using the logic you've already employed, one could conclude that the entire anthology of philosophical texts also have zero bearing on reality because "they're all made up".