As Scalzi says:
Science fiction is and always has been a consumer genre; its roots are in engineering and pulp magazines, not in academia. This is why sales matter in science fiction; more directly than nearly any other genre, the people who eventually write science fiction are the people who grow up reading science fiction. People start writing literary fiction as they tumble through writing programs at Sarah Lawrence or Bennington or Iowa because that’s what they’re expected to write and they want to impress their professors and fellow students; people start writing science fiction, on the other hand, roughly ten seconds after they set down The Star Beast or Ender’s Game or Snow Crash because they get done with the book and think, holy crap, I want to do that. Academia generally wants you to show you can write; science fiction generally wants you to tell a story. It’s the storytellers who get picked up by the next generation of science fiction writers, and whose work is used as the blueprint for their own works.