Gene Roddenberry said that the real purpose of the starship Enterprise was to serve as a vehicle not for space travel but for storytelling. Beyond all the technical wizardry, even a techie such as myself recognizes that what makes Star Trek tick is drama, the same grand themes that have driven storytelling since the Greek epics--love, hate, betrayal, jealousy, trust, joy, fear, wonder.... We all connect most closely with stories that illuminate those human emotions that govern our own lives. If warp drive were used merely to propel unmanned probes, if the transporters were developed merely to move soil samples, if medical scanners were utilized merely on plant life, Star Trek would never had made it past the first season.
Isn't that a perfect commentary on good fiction? No matter whether a story takes place during the Civil War, or on a Pacific steam liner, in the steaming jungles of Africa, atop frozen Mt. Everest, or even aboard a futuristic spacecraft, it's human drama (or extra-terrestrial drama) that makes the tale come alive. Sure, a story needs a setting, and the setting must be realistic. However, if the setting ever becomes more important than the characters, then the story will suffer for it.
Perhaps you've gleaned some interesting insights into fiction from unexpected sources. What have you learned? Or what observations about great fiction have you made on your own?