As the Guerrilla Girls, everyone's favorite ape-masked, feminist art activists (pictured above), will tell you, not only are women artists underrepresented but the female form is grossly overrepresented in most museum collections, often in violent depictions by male artists. Women have toiled under a muse complex (and the accompanying madonna-whore psychodrama) for centuries, and it's reflected in the content of art museums and art history.
The Anonymous Female Artist (aka, Militant Art Bitch) tells a story of a Los Angeles artist fed up with the current fetish for work by artists under 30 as well as the expectation of "eccentric, bizarre, stupid, fluffy crap from artists, especially women artists." That artist fulfilled a fantasy by hiring an under 30 actor to act the part of the artist behind her work. There's an element of ageism in that story as well as sexism, but it's all part of the greater problem that the Tate story has brought to the forefront.