Does a SAHM benefit society?

I just read an interesting post at Wheat and Tares called We Don't Value Motherhood.  Parts of it seemed a little conspiracy-theorist to me, but it did have some good points.  One fault, I think, was the leaning on using monetary gain/economics to measure success.  One commenter (Bonnie) pointed out that "the PotF [Proclamation on the Family] ... replaces economics with family as the center of a healthy focus" reminding us that we don't need to measure success by money.

Bonnie also left a comment about how she works with under-privileged single-parent families and how a SAHM (in a 2-parent family) is a great benefit, even if not easily measured:

...The issues of contributing to society are wholly separate, IMO, from economic issues and I’m just so tired of everything having to boil down to a dollar value. I am a working mom, and I’ve had to leave my children in order to make sure we eat. It is much harder to be there for things that they need someone to be there for, and those things make for stable adults who have fewer health problems ... a better sense of their place in the world, better emotional health, better communication skills, and better problem resolution abilities. I spend a lot of time praying that the time I’m there is sufficient.

Before the working moms unload on me (I’m one of you, just in case that wasn’t obvious in what I already said), for crying out loud, OF COURSE I’m not saying that any lazy, TV-watching, kids-yelling, bon-bon-eating person with female organs is all that is required for children to arrive neatly-combed and diplomaed into adulthood. But we increase the stability of children when they have a strong parental influence all day (as is age-appropriate), especially in the earliest years.

 I KNOW we are all doing our best. I’m saying that in ideal situations, a nurturing influence (male or female) during the under-7 years who is able to address situations immediately with very impressionable children creates the best hope for self-calming adults. Lack of self-speech, or the ability to consider consequences and make short-term sacrifices, is the single most important component holding a family in the grip of generational poverty. Moms who are focused on this can do this. And moms who are supported by dads and a society to do this don’t lose their minds.

I know, hawkgrrrl, that you are not a fan of role division, but I am, not just because the church “says so” but because in cultures where there is a lot of poverty, when this nuclear unit can function with role division, poverty goes. ETB said that you don’t take people out of the slums, you take the slums out of people. That’s what we have to do. I think role-division can really help with this, and the benefits to society are no less crucial just because they’re less measurable.

Also in a comment, the author of the post mentioned how she doesn't mind role division (splitting up parenting duties), but does mind role prescription (being told what one must do/like, etc.).  I've heard that a lot on blogs, but honestly, I can't say I've ever felt that.  I'd vomit if anyone made me, or told me that I should scrapbook because I'm a girl.  No one's ever told me I shouldn't mountain bike or sheet rock or go to college because I'm a girl.  Have you felt pushed in to liking/doing certain things because of your sex?  Apparently it happens, but I missed that one I guess.

In regards to staying home and being a primary nurturer, there are some pretty strong factors that make it more logical for the woman to stay home:  how about breast feeding and the evidence that females are likely better nurturers than males?