It's not so important whether or not Jeffrey Robinov, head of production for Warner Brothers, actually said, "We are no longer doing movies with women in the lead." It's that there's no surprise in it.
In 1997 I wrote and directed All I Wanna Do, a little $5 million film about an all-girls academy going co-ed, starring Kirsten Dunst, Lynn Redgrave, and a mostly female cast. It was Animal House or Porky's, only for teenage girls, so they could have their very own horny bad-behavior movie. Miramax, then run by the Weinsteins, bought the US distribution rights. They tried recutting my film for the young male audience, which reduced it to about 65 minutes. Then they declined to distribute it at all. We don't know how to market to that audience, they said. It's just not there. This was when I first heard the industry-accepted principle: that females don't go to movies about females. Way! At the multiplex, they are more apt to go to the films their boyfriends/husbands want to see.
There have been exceptions to this principle (Devil Wears Prada), but how easily they are forgotten when the scale usually tips the other way (A Mighty Heart, Evening, Away From Her). Women's films are "soft" and so are the returns.
After all, these executives have their asses on the bottom line. So if you want to mount a protest against Warner Brothers, don't boycott their films. Prove them wrong. Go buy a ticket to The Brave One (you'll at least see an outstanding performance by Jodie Foster). Too violent for you? Go see The Jane Austen Book Club: by and starring and for women, a well-reviewed adaptation of a popular book. It's languishing at the box office. Where are the sistas?
(P.S. My film did ultimately find its natural audience and did just fine -- on video.)