> People have no obligation to include anyone in their writings.
Except this isn't the point I was making.
People in a privileged position are obligated to be more inclusive, because their position is different. This is why, for instance, it is problematic that the POTUS explicitly endorses Christianity as a matter of state. While I concede that it would waste political capital to be inclusive, it remains "immoral and wrong" for him to exclude non-Christians, atheist or Hindu or whatever, simply by weight of tradition.
In this case, males are in a privileged position. Failing to be inclusive, even by omission, is exclusive. We could make this about browser wars and point out how problematic it is that rendering engines are becoming monocultural. We could make this about the predominance of Windows and the implicit assumption that everyone who uses a computer must have a two-button mouse. We could make this about economics and ask why anyone would find it in their self-interest to not increase their disposable income.
It is a responsibility of those with the privilege of dominance to actively seek out ways to be inclusive. It is similarly the right of those who are disadvantaged to protect themselves when excluded, even if it's through exclusion themselves. Both actions are stepping stones towards a stronger egalitarianism.