Of Mice and Men is set in a male environment where there are three types of women: the imagined nice girl for settling down, the prostitutes for a drink and a trick, and Curley’s wife, who is their daily representation of what to expect from the other sex. Women are a kind of absent symbol, only there to highlight the men’s failings: the men of the ranch can’t settle down, so they go to whorehouses. As the "girl next door" type is only a fantasy, the men basically reduce the women around them to sex. As George states, at least with prostitutes, "you pay for what you get." While Curley’s wife is a sexual object, she can’t actually provide any sex (because she’s taken) – all she can really offer is trouble.
Curley’s wife is a caricature of the problems suffered by women in small agricultural communities during the Depression. Though she’s an awful woman, she does suffer from real affliction and prejudice.