I don't think the article is pushing for women to stay at home. In fact, the author notes that her husband stays at home. I know several families where the father is at home. Many women earn more than their husbands do. And either partner may be in a better position to accommodate working from home or taking time out from a career.
The article instead looks at the financial realities of having one spouse stay at home. Often, people underestimate the costs of working. If one person wants to stay at home, it is not a loss of an entire salary. In fact, it may not result in a loss of income at all. The same logic could be applied to a situation where both partners were able to scale back to, say, 20 hours a week. By avoiding childcare costs and reducing some of the other costs of working, they might not be in such a bad position. However, in the US, I see there are some taxation issues that arise when both partners are working, at least from my quick look at the article.
Some time ago, I wrote a post on the work-life balance
that consulting can bring. But my point about eeking out a small income would work for those who want to work part-time or even not at all (when it comes to paid work). Some tax and social payment benefits arise from a lower income, making it efficient for one person to stay at home, at least in Canada.
Leaving your child in daycare from infancy may mean constant turnover of caregivers, limited one-on-one care for your child, a need to use formula and other important factors. I think the above article is just showing that, if you're heading back to work only (or significantly) because you think you can't live on one income (or two modified incomes), you might want to run the numbers.