Excluding traditional songs I think one of the major problems is that most female songwriters write about "feelings", and love and its many problems. Male writers tend more to write about "life" and its many problems.
Male writers are more likely to write in the abstract, creating a character or telling a story. Women writers tend to write more from the personal I/me point of view.
Yes there are exceptions others will now pile in to quote, but I'm making a generalisation based on listening over many years.
By the way, I have many cds by female writers as well as male and enjoy them equally.