Just yesterday I saw a feminist named Camille Paglia address this very question, and I was pretty surprised by the answer. I'm still processing her statement, and I am far from being ready to agree with her.
She said: "There is no female Mozart because there is no female Jack the Ripper."
She says that women "cluster at the median points of the intelligence rank." There are not large variations. They don't produce great geniuses but they also don't produce morons and the worst criminals. Men pursue extreme visions whether they be good ones like going into space or horrific ones like shooting up a church or school.
You can hear here explain the statement with her own words in the video below. Skip to the 4:00 mark to listen to her build up to the statement, or skip directly to 5:35 to hear her repeat the quote and explain it herself. I hope I've done it justice.
Personally, I just think there have been no historically great women orators, philosophers, composers, etc because these areas have been male-dominated for so long. In fact, I'd say there are already women alive today or on the way who history will look back on with as much reverence and respect as we put on the Mozarts and Platos.