Why is Curley's Wife significant as a character in Of Mice and Men?

Curley's Wife is both significant as an accurate historical portrayal of women in 1930's America, and also as a substantive catalyst to the tragic events in the novels plot.

Firstly, I will deal with the historical issue. Curley's Wife is the only female in the novel, and doesn't even have her own name - instead, she is merely the property of Curley, and this makes reference to the explicit gender inequality seen in the 1930s. Other characters like George even call her "jailbait" - and we see from this a graphic over-sexualisation of her character, added to by the overuse of the colour red when describing her, as often we connotate red with both danger and sex. 

Secondly, we see that Curley's Wife as a character is an important plot tool used by Steinbeck to add tragedy to the book. She begins as a similar character to Eve in the Garden of Eden -  a seductive, evil temptress who can do nothing but add harm to the lives of George and Lennie. She brings evil into mens' lives by tempting them in a way they cannot resist. Eventually, she brings about the end of the dream of Eden, the little farm where George and Lennie can live off the fat of the land. Her death at Lennie's hands means the end of George and Lennie's companionship and their dream. We see, therefore, that the entire plot rest on Curley's Wife and her character traits.

The two points above highlight an irony both in the text and in history - if women such as Curley's Wife play such an important role in both the plot development, and life in general - why, historically, were they subjected to second rate treatment?