Science fiction is not a genre
by look i have opinions
This has been said many times, and it should really be a trite and duh-obvious thing to say by now, but science fiction is an element of worldbuilding, not a genre. It’s true that science fiction is associated with certain genres, such as adventure fiction, preachy psychophilosophical fiction, cautionary tales about society, straight-up horror, and fiction whose primary purpose is to explore or illustrate scientific ideas. But those genres have nothing in common with each other except worldbuilding elements, and hardly anyone uses “science fiction” to refer to any particular one of them. So calling science fiction a genre is a taxonomical error. At best, the term is a marketing category, a way for potential readers to narrow down their searches.
Every time I see people debating the overlap between science fiction and literary fiction, or between science fiction and great literature, this is the first thing I want to yell at them. Then I hate myself a little for being so obvious. Then I hate everybody else for making me think about something so obvious.
(All this also pretty much applies to fantasy and vampire fiction and anything else you could place under the “speculative” umbrella.)
Whether contemporary literary fiction is a genre strikes me as more open to debate. I’m inclined to think that it actually comprises two or three genres that share certain editorial values—high-quality prose, psychological/thematic depth and subtlety even at the expense of entertainment, distrust of unambiguously happy endings.