Whenever I watch something geeky my Dad always sarcastically asks: "Is it about real life and real people?" But the thing that science fiction "haters" always ignore about science fiction is that it's never about the aliens. All the cool technology, space dogfights, shields to maximum, giant robots, green creatures, "Make It So" and ice planets are all just spectacle. Enjoyable, to see the heights of human imagination, but ultimately second place to what makes science fiction great.
The same thing that makes War and Peace a great novel makes The City and the Stars by Arthur C. Clarke great. The greatness of The Count of Monte Cristo is the same greatness of the Hyperion space saga. We applaud these books for what they have to tell us about the nature and being of humanity.
All good stories rest on this point. But what makes science fiction so interesting is that it offers us views and thoughts on humanity via displacement. By removing the ordinary and inserting us into the extraordinary we are removed from are usual touchstones of reality and become, without even being aware of it, all the more open to new ideas. As the setting is removed from the norm so our preconceptions are not immediately engaged.