At the time when the novel rose into its own, during the course of a man's education, he was taught to read and write in Latin and Greek. A woman was not.

A woman might have learned modern languages (though many did not), but they were generally not thought capable of the type of study it took to learn these "classical" languages, and one reason that women did not go to university was that they didn't have this necessary preparation.

These ideas lead to the impression that women could not handle "serious" learning and reading, and they were left to read these supposedly lighter, more fanciful stories. They were written in their own language, and wouldn't hurt a woman's feeble mind :)