Feminism as a whole seems to have an uneasy relationship with motherhood and domesticity. It doesn't matter whether you look at radical feminism or liberal feminism or whichever branch of feminism you care to examine. In my view it's a major shortcoming and failure, because 80% of us give birth, and a large majority of mothers take time out to be SAHMs for at least the first important months of their children's lives. And the overwhelming majority are dealing with the bulk of domestic work.
Liberation, again no matter which version, seems to be viewed only through one lens, that of freeing us from domestic work and being SAHMs. A shortsighted aim that would result in harm for many children (in case they're unaware, that's been done before. Including in the communist country I grew up in. I was one of those children. It was absolutely undeniably unequivocally harmful to the children who suffered through it.)
But even today feminists devalue women's domestic work and Ruth and Sarah are not the only and certainly not the first feminists to look down on SAHMs as domesticated zombies.
I've come to the conclusion that true liberation necessitates that we resolve this conflict because it doesn't just arrise from patriarchal oppression. There's the simple fact that it benefits the child to have its mother provide this vital care in the first stage of its psycho-social development.
(Ignoring for the sake of argument here that there's a small percentage of mothers whose children would benefit more from being almost in anyone else's care than theirs.)
But in thinking of us like that, Ruth and Sarah do nothing more than follow their programming (or female socialisation if you will). It's a very patriarchal opinion to hold and it serves a specific purpose in driving a wedge between feminists and ordinary women.