There are dozens of isolated exceptions, but the point survives. Most conspicuous among the failures are the women of Conrad, Faulkner and Hemingway. The beginning of my guess at an answer paraphrases that of the English critic David Cecil. He suggested that the imbalance is owing to a fact of family organization. And in our own constricted nuclear family, they, like their brothers, are deprived of the resident grandfathers and uncles frequently present in earlier homes.
Men are the creatures who leave after breakfast and return at dinnertime.
Most women, then, are excluded from close psychic relations with men until the women are pubescent. However partial, the explanation is grounded in prevailing gender structure as far back as we can see in Western civilization - the rigid early assignment of male and female roles and duties. That structure has unquestionably benefited the male children, who become male writers, at the expense of the female. No wonder at all, then, that the imbalance exists. There are the women of Aeschylus, Sophocles, Euripides and Shakespeare.