Complex sentence: In the late 1960s, a new movement of science fiction writers, the "New Wave", arose, which rejected science fiction's pulpy background, and absolutely scorned the term "sci-fi" as being associated with bad monster movies.
Split into simpler sentences: In the late 1960s, a new movement of science fiction writers, the "New Wave", arose. It tended to reject science fiction's pulpy background and to scorn the term "sci-fi" as being associated with bad monster movies.