We're drawn to both because they put us in the characters' positions. And when we're through watching, reading or playing, we're back in our world, having, for better or worse, learned a little bit about ourselves.
The Implausibility Factor
Science fiction's main draw to the general audience is its escapism. Sci-fi isn't just veiled morality tales. Even if we don't sense the message in a particular work, the medium is often enough to entertain. The genre's appeal would be diminished or, more likely, entirely extinguished if the stories weren't themselves enjoyable.
Living in a sci-fi world is utterly unattainable, but our imagination takes this as a challenge, allowing us to escape into those worlds more fully than with other genres. Typical stories set in the Real World have real-world restrictions that hamper our ability to imagine ourselves in them. Sci-fi escapism, then, doesn't seem to fade away into our subculture's consciousness like other adventure stories do. While this year's big non-sci-fi adventure movie might be an immediate success, it's unlikely that it will have the staying power of Blade Runner. Joss Whedon's Firefly is still selling strong on Amazon years after the little-watched TV show was abruptly canceled. Our imaginations just can't carry us that far into a real-world situation, but when you're dealing with an impossible scenario, everything is possible to imagine.
Science fiction promises us that if our surroundings were different, if a new technology were invented or time simply passed, we could be the hero in the story. We needn't be extraordinary; we need only exist in that world. We can imagine so easily what we would do in those situations, with that technology.
"If only I'd been born on Tatooine, I could have saved the galaxy" is easier and more fun to imagine than trying to create a scenario set in today's world where I could achieve the same thing. With sci-fi, the blame for our lives not being extraordinary is placed on the universe and not ourselves. This allows us to explore every inch of those universes unimpeded, and wonder what our lives could be like if we lived in that galaxy far, far away.
The sci-fi games BioShock, Halo 3 and Mass Effect were among the greatest commercial and critical successes in videogames last year. Halo 3's success, in fact, was unprecedented. Mass Effect and BioShock were touted for the moral choices they presented. Both games used the genre to encourage the player to explore their own humanity, and humanity as a whole, in classic sci-fi form. BioShock was able to do this without even being set in the future, but by harnessing the same techniques afforded by traditional sci-fi, like foreign technology and a futuristic environment.