Funny thing is, it used to be 'put in practice', at least to a greater extent than now. There are lots of factors affecting it, not limited to: the rise of feminism, the idea of a 'no fault' divorce, the lack of respect for marriage, the lack of committment to and understanding of marriage, the prevalence of marriage for 'love' which is a relatively new concept, the increased egoism [people are in a marriage for *them*, not for the other person or the unit], desire for instant gratification, inability to plan ahead and work for future outcomes [a marriage isn't perfect all the time, and does require work--too many people give up after one fight or whatever], etc.
Statistically speaking, a child raised in a two-parent household is less likely to commit crimes or be a lot less well-off than his parents.
Does that mean *every* two-parent household is better than *any* single-parent household? No, I never said that. I'd certainly rather a child be raised by some of the single moms I know than by, say, a marriage between Michael Jackson and Susan Smith, or an abusive dad and drugusing mom, for example. Of course, I think lots of those 'failed marriages' should never have happened in the first place, but that's a whole other story.
A stay at home mom who wants to work is not necessarily more 'harmful' than a fulfilled working mom. It depends on how 'adult' that mom is; adults often have to do things they don't necessarily want to do, because it's the 'right' thing to do. If the stay at home mom stays at home complaining to her child about how Daddy is a throwback and wants her barefoot and pregnant, and talks about resenting the world or whatever, then yes, that can definitely skew the child's perception of the outside world, though I don't know if that's definitely harmful [the badmouthing of the father is, however]. If she resents Daddy and takes that out on him or the child, then yes, that's bad as well. If she approaches it like "Sometimes we do things we don't necessarily want to do, but we do them anyway" that's a good, adult way [although my phrasing is off--that implies she doesn't want to be with the child, which is a *bad* thing for the child to hear]. The whiny "I don't get what I want", or the lack of constant "'satisfaction", is a sign of a child, not an adult, and is equally harmful to the child.
How do I put this into practice? I honestly don't know. As a libertarian, I'm generally against lots of 'social engineering' type laws, and I am quite hesitant of the "Won't somebody think of the children?!?" argument, but this is one case where there is a definite link. Ultimately, I'll admit, I'm selfish. My main goal is that I want my child/children to benefit and succeed, so the best thing I can do is show him that while marriage and hard work isn't easy, working on it is worth it, and show him, not just tell him, what I think it means to be a good person, a good father, and a good husband.