While that certainly makes it a bad place for the sexism discussion, that certainly does not make it a good place for technical discussions!
Sure, whenever there's a massive imbalance between the genders, it's going to be less productive than when there's a balance. It also doesn't help much if the sexism discussion occurs among a group of 95% females - which is typically what happens.
On the contrary, that would make it better. We can have a rational discussion without all the drama. ;)