I think it's mainly because the website is geared towards dating/relationships which are commonly female topics. This might also be a bit of a generalization, but girls tend to like discussion and asking for input more.
Because females want to know a guys perspective and if they ask their female friends they might sugar coat it. Most women are open books and are not shy voicing their opinion. Where as males seem more timid about how they really feel and this site is a great way to get the brutal truth.
Well the website is called girls ask guys. But also neither gender really understands eachother. Like women and men act differently. Women are more complex and have more questions and drama issues. While men are more straight forward or just dont care. So women have more to say and women wanna know they are right. I don't know why but they do.