I’m not saying either side is right or wrong, but I do get yotsuya’s perspective.
If you worked at a bookstore, for example, and you had to choose whether to put Star Wars books in the fantasy section or the science fiction section, which section would you put them in?
But Star Wars books treat the science of the SW universe differently than the movies do. The TFA novel actually explains how Starkiller Base’s primary weapon works and how it can destroy planets while on the other side of the galaxy. The movies don’t do that. In the movies, the science takes a backseat and is almost never explained.
That is the difference between movies and book and has nothing to do with genre. In a movie you only deliver what you absolutely have to in order to tell the story. In an book you have more room to flesh out the world. No movie is as detailed as the book.