Reddit mentions of The Second Shift

A fair assessment.

Other explanations include:

1.The decline of the two-parent family, for instance, is almost certainly depressing life satisfaction for the women stuck raising kids alone.

• Before 1970, most unmarried mothers were teenagers. But in recent years the birthrate among unmarried women in their 20s and 30s has soared — rising 34 percent since 2002, for example, in women ages 30 to 34. In 2007, women in their 20s had 60 percent of all babies born out of wedlock, teenagers had 23 percent and women 30 and older had 17 percent.
  
  
• Much of the increase in unmarried births has occurred among parents who are living together but are not married, cohabitation arrangements that tend to be less stable than marriages, studies show.(source)
  
  
  **2.**"The Second SHift"
  
  
• In this landmark study, sociologist Arlie Hochschild takes us into the homes of two-career parents to observe what really goes on at the end of the "work day." Overwhelmingly, she discovers, it's the working mother who takes on the second shift. (source)
  
  
  
  
  This NYTIMES column provides more insight
  
  Liberated and Unhappy

A part of feminism has always been about making having a baby be a choice for a woman rather than a requirement, but if that comes across as ignoring the plight of mothers, well, that's not intentional. For me personally the fact that women have taken on both the burdens of being a "provider" and taking care of children and housework is a big deal to me. I don't know if this counts as feminist, but this idea has been studied in detail.

This is entirely guessing, but there is a good chance that if she hadn't quit her job the woman in the op's comment would have been doing both engineering and child care, without that much help from the husband. That's extremely common, and sucks.