The point is that people are therefore not encouraged to seek to get across the border to bear their children in Australia, in this case—or the United States—so that their children will be automatically granted citizenship by birth.
Ainsi, les femmes étrangères ne cherchent pas à se rendre en Australie—ou aux États-Unis—pour y accoucher uniquement afin que leur enfant obtienne la citoyenneté du pays de naissance.