What’s wrong with wanting a baby?

My Google alerts (great service!) brought to my attention a scathing review of Madelyn Cain’s The Childless Revolution. Jessa Crispin writes on her Bookslut page that “those who choose motherhood and those who choose childlessness are on opposite sides. Once you’ve chosen, you’re alien to the other group.”
Well, I have noticed a divide between the “childfree” and the “breeders,” but can’t we reach across and find a peaceful way to relate? A lot of us who don’t have children wish we did, and some of those who have kids wish they didn’t.
In her review, Crispin begins by telling us Cain isn’t qualified to write about childlessness because she had a child when she was almost 40. The fact that she had trouble conceiving for all the years before that doesn’t count. And the fact that she had an intense desire to be a mother puts her on the “other” side, the breeder side. Do you agree?
Crispin goes so far as to note how many pages Cain devotes to each of her three sections, the childless by choice, by chance and by happenstance. The childless by chance get the short end, she says. “This isn’t really a book about being childless. This is a book about women who wanted children but didn’t get them.”
She also also complains that Cain’s book is poorly written and that it has too many personal observations. I disagree. The issue of having children or not having them is personal.
All this makes me sigh. I hate to see women dividing into enemy camps. Also, I happen to think the Childless Revolution is fine book. See my review on the Childless Resources page on my childless by marriage website.
What do you think? Can a mother write about childlessness? Are mothers and non-mothers so different they have to live in separate worlds? Have you read Cain’s book? What do you think?