You may learn things about the expectations of those that read romantic novels, some of whom you may want to date. Fiction is instrumentally useful insomuch as it teaches you the cultural context others are immersed in. It's probably worth it for most peoples to learn how fiction works and why it is appealing, something that can't be done exclusively through non-fiction. Spending ~10% of one's reading time on fiction isn't an unreasonable use of a rational person's time, disregarding the pleasure of it entirely. At least, this is my rationalization.