This frames the decision to dedicate more time towards childcare than work as a something thrust onto women by societal expectation when women would rather work. Studies indicate that only 20% of women would prefer to work full time after having a child, with the rest preferring part time work or staying at home with the children. Furthermore, 70% of women with children that are currently working full time responded that they would rather be working part time or not at all [1]. By comparison the majority of men indicate that they would rather work full time.

Women and men both have to choose between their careers and spending more time with children, and their choices reflect their preferences. One can make the argument that this is indirect sexism - that women's preferences stem from sexist social influence. But the fact remains: most women don't want to work full time, and the lower rates of women working full time after having children is reflective of women's preferences.

1. https://www.pewresearch.org/wp-content/uploads/sites/3/2010/...