(I am not defending the above proposition. I am just considering how people respond to it.)
This suggestion should be axiomatic to anyone who argues there is no fundamental differences between the sexes aside from their reproductive capacities. Yet it is those who argue most strongly in all other areas that equality must be assumed who are most likely to strongly promote a view of the moral superiority of women and the inherent immorality of men. Feminism, for all its demands of equality, is based on assertions of sexist inequality.
Feminism was never a demand for equality, and I have no interest in pointing out their contradictions here. I am interested in understanding how they view moral nature and why that is important for their platform.
Feminism elevates the feminine moral nature while denigrating the male nature. Women are compassionate and capable, men are violent and lazy. There is no one at a baseline morality. What would be the baseline is the non-political view which says everyone is human. This default view of moral equality is twice challenged by feminism, both to raise up women and to push down men.
The rhetorical value of this view is apparent when anyone tries to discuss the true moral nature of either sex. If you claim men are not morally deficient then you are defending violence against women. If you say that women are not angels, your are misogynistic. If you would make the shocking claim that the sexes are morally equal, you are a violent misogynist.
While the moral sexual dimorphism presented by feminism serves them in many ways, one of the most immediate is the way it blocks debate on the issue. Simply by presenting this view of moral inequality they make any attempt to argue it politically incorrect. Most importantly it completely blocks the possibility to argue that the sexes are morally equivalent, since that is now the most immoral possible position.