This is part of the cause of what the article says is "women who otherwise might be promoted to more senior jobs". If there is someone else - woman, man, alien, whatever - who is equally qualified but who is also completely focused on their career, then why would a manager not reward that person and instead choose the person who is not willing to dedicate an unreasonable amount of time to work? What manager would not choose the person with more time to dedicate and is actually willing to dedicate that time? You're going to get more out of the singled-minded person.
It seems to me this is really an issue for these women at home, not work. Why would they not have a conversation with their husbands about this? If the wives are making more money and have more prospects and opportunities for advancement over their spouse - the spouse should theoretically be willing to agree to be the one who makes the sacrifice when surprise child-related stuff pops up. Right? So it's probably likely that either their spouse is making the same or more, or they simply aren't having these conversations at home and instead are asking Amazon to make their lives easier. I'm not sold that this is an Amazon problem.