>"So you claim that the other sex is not capable for skilled presentations, how dare you!"

I don't think it's particularly hard to defend yourself against that. You simply claim that for some reason women don't want to come to your conference so there wasn't enough submissions, and then promise to aim to do better. Maybe it's just me who feels that intent to fix is better than trying to cover up our problems. If i had any interest in this conference now I'd consider not going.