Question

At the end of chapter 6 of tractate Yevamot, it seems that without the claim of “a staff for burial,” a woman has no right to demand a bill of divorce from a husband who is unable to father children. And this is very puzzling, since surely a woman’s deepest desire and her whole life (at least before women became academics…) is to bear children and raise them on her knees, as we find for example with the matriarchs Sarah, Rebecca, Rachel, and Leah. So why would that reason not suffice to forcefully claim a right to a divorce?