I'm sure there's a definitive reason, but I'm going with my usual default: People are dicks. People with anonymity via the Internet are given the opportunity to be Uberdicks. Some of them take it. I haven't run into many women online, but with one exception, I've been kind. The exception? She called me out and teabagged me. I hunted her down the entire next game and punished her for her insolence. Gender was not part of the equation.