It’s always interesting to see a lesson in accounting and finance from someone who clearly doesn’t know much about either. If you have a couple with one person making $100K an the other making $50K; they are not kinda, sorta, making $75K each. If you don’t believe me, ask one such couple to review their annual budget under scenarios where they each quite their respective jobs and see the results. This is like saying if a couple goes out running, one doing 5 miles and the other doing 3, they actually did 4 each. This is the difference between actual math and math you do as an ideologue to make yourself feel better.
That is not to say anyone should have to quite their job in the scenario outlined above. If you love what you do and/or have a promising career path with higher earnings potential, that is a strong argument for staying at it.
Regardless, whether a person decides to stay at home with the kid(s) or work full time is a personal choice. The inherent prejudice in this piece: that smart/ambitious women are incapable of being happy raising a child is just more sexism. With the implied codicil that if you do choose to be a stay at home mom (or dad?) you are either profoundly unhappy or lacking intelligence and ambition. Neither of which is actually true.
It always amuses me to see people claiming to support equality belittling women for the choices they make.