This is likely to be a disputed position, but Forest Green Feminism believes so, and argues her point. She is very careful to point out that she does not deny male privilege or the fact that motherhood is a form of compliance, but she argues that beyond that motherhood does confer privilege over non-mothers.
First, the aggrandizement of motherhood is really about the favoring of sons — their creation, their nurture, their ultimate elevation into the power structure as high as they can go based on other factors, like race, class, and their own level of conformity. It is the duty of mothers to raise acculturated sons. Rape and male violence (down the hierarchy) are culturally-accepted norms. Mothers are to defend their sons against charges of rape and other forms of violence against ‘lessers,’ usually women but also marginalized men. And mothers do!
When I suggest that women’s loyalties must be to females, foremost, and against their misogynist sons, I get resistance. When I suggest that if a son rapes, is known to have raped, loyalty has to be to his victim, the female being, and he needs disowned, I hear, “How can you say this — he was born from my body, he is my child!?!” I can say it because it is high time our loyalties are to female humans. And I can say it because women defending the outrages done by patriarchy, even in the forms of their own sons, is a significant part of the problem. Patriarchy is maintained by unquestioned allegiances by the many, including the terribly-oppressed. All systems of subjugation can be reinforced this way (and usually are).
Second motherhood is, itself, loyalty to the norms of heterosexuality. I was at the time actually a part of the Great Lesbian Con into Motherhood. Lesbians everywhere were having children, and I wanted in! I read everywhere of women’s biological clocks and discovered I, too, had one! Is there an internal urge to procreate? There may well be, although I’m not convinced there is. Still, any valid urge or instinct is easily manipulable by incessant cultural pressure. Even more so if it’s subtle and proffered by members of your own minority group. The fact is that Lesbian Motherhood was an act of assimilation, complicity by its very nature. And I was a part of it. (Damn me!)
Third, motherhood brings rewards and attention at the expense of childless or child-free women. Women who eschew childbearing are “selfish,” and more.