It's no males at all.
We understand that a lot of males are perfect gentlemen and don't cause any problems,but a few bad apples can spoil the bunch.
Have you ever heard of Schrödinger's box?In a way our reasoning is kind of like that.You don't know if a male (the box) is one of the bad apples or not until you get in a game with them.So for some of us it's far simpler to just remove the box (males) from the equation,which eliminates the risk.
Of course many of us still play with males.We don't all exclusively only play with members of our clan,and many of us are members of multiple clans.Sometimes we just want to play with other ladies for a change,which isn't so bad,is it?