Right? Well, no. The usual answer to anyone who questions this perceived wisdom is that historical times were sexist and the authors who follow this pattern are just being accurate. Instead it's more that men wrote history and so we get men's view of history. Oddly, there have always been many women who refused to accept their place as defined in these traditional histories but they are still regarded as unusual. A few examples who spring to mind are Jean of Arc, a successful general, Elizabeth I of England who ruled in her own right from 1558-1603, Isabella I of Jerusalem, also a queen regnant from 1170-1205 and these are only a few women prominent in political matters. I haven't even started on the scholars, scientists, authors and artists.
Tansy Rayner Roberts posted about this here a few days ago and this has now been reposted here at Tor.com where there has been much discussion on the subject. The comments make interesting reading. As an historian Rayner Roberts has a useful perspective and particular interest in this area and she has now posted a list of all her posts connected to the subject and on feminism generally here. If you missed them the first time around, and whether you are interested in feminism or not, I think they are worth a look.