Genre is a subjective concept. One person’s crime novel is another person’s work of existential angst is another person’s romance, depending on what aspect of the novel they focus on. It is often used pejoratively (as in “that’s just science fiction”) and as such is sometimes avoided by mainstream authors (as in: “it might be set in the future and involve as yet undreamed of biological sciences but it’s not science fiction”). But, in reality, genre is just a reasonably well developed sorting tool. Genre is an easy way to find what you like and a great way to organise a book shop or, in this case, a book review website.
Every review on the Pile is catalogued into one or more genre categories. Those that don’t fit any other genre tend to be catalogued as “literature”, but this is just a catch all and is not meant to suggest there is a genre that is not itself literature. It just sounded better than “other”.