SF doesn't play by the same rules, and some of it (like Dune) is political fiction, which doesn't get any coverage at all in other genres.
What seems to make novels stand out is psychological insight. A lot of literature fakes insight by having characters that agonise melodramatically over their lives.
Dune scores off the scale on insight, with less of that ersatz psycho-angst and plenty of the real thing.
