WonderBranding talks about the circulation numbers for newspapers, focusing on the loss of female readers:

A recent post addressed the news that women are abandoning newspapers like rats a sinking ship.  They feel disconnected and ignored when it comes to content, which is 70-80% male-oriented.

Interestingly enough, my wife's comment when I mentioned this wasn't the male oriented stories - it was that men take newspapers to the bathroom, and woment are happy with reading on a PC. Now, I'm not sure how this actually works out - men have always taken papers to the bathroom, and it's not as if there was some golden age when there were more stories focused on women either.

Bottom line? I suspect that the dropping circulation is simply part of the larger trend, unrelated to any kind of latent sexism thing.