There aren't more lady songwriters for the same reason that there aren't more lady doctors or lady accountants or lady lawyers; not enough women have the time for careers.
“Middle age is when a guy keeps turning off lights for economical rather than romantic reasons.”
“After mature consideration it was unanimously agreed, that, to prevent as much as possible their attempting to return and molest the settlers that may be set down on their lands, a sufficient number of vessels should be hired with all possible expedition for that purpose.”