Some hypotheses:
1) These are stories that the posters and commenters can be reasonably sure a larger fraction of readers will be familiar with. Eliezer can reference Yoda or Frodo and we will know what he means, in the same way that I can say “Moses” or “Noah” and any member of any Abrahamic religion will know what I mean.
2) Science fiction and sometimes fantasy are genres that lend themselves to introspection and philosophical heroes. By eliminating many trappings of the real world, they can get at the heart of otherwise abstract concepts. Drizzt Do’Urden can wax eloquent on racism without sounding like a “liberal” or whatever, because he is a drow elf who escaped his heritage and has realized that not all orcs and goblins are evil and so on, and not a human in the world as it actually exists.
3) Sci Fi stories allow writers- and readers- to play directly with deep assumptions, and violate normal rules. They expand the set of possible worlds (not maximally, but by quite a bit) that we have available for contemplation and comparison. Historical fiction can’t ask what it would be like to put the entire future of humanity in the hands of a lone villain locked in a cave—even the POTUS couldn’t destroy humanity all by himself. But if, for example, you’re worried about friendly AI, then sci fi or fantasy might be a useful mirror in that regard.
Some hypotheses: 1) These are stories that the posters and commenters can be reasonably sure a larger fraction of readers will be familiar with. Eliezer can reference Yoda or Frodo and we will know what he means, in the same way that I can say “Moses” or “Noah” and any member of any Abrahamic religion will know what I mean. 2) Science fiction and sometimes fantasy are genres that lend themselves to introspection and philosophical heroes. By eliminating many trappings of the real world, they can get at the heart of otherwise abstract concepts. Drizzt Do’Urden can wax eloquent on racism without sounding like a “liberal” or whatever, because he is a drow elf who escaped his heritage and has realized that not all orcs and goblins are evil and so on, and not a human in the world as it actually exists. 3) Sci Fi stories allow writers- and readers- to play directly with deep assumptions, and violate normal rules. They expand the set of possible worlds (not maximally, but by quite a bit) that we have available for contemplation and comparison. Historical fiction can’t ask what it would be like to put the entire future of humanity in the hands of a lone villain locked in a cave—even the POTUS couldn’t destroy humanity all by himself. But if, for example, you’re worried about friendly AI, then sci fi or fantasy might be a useful mirror in that regard.