Absolutely this. This is fundamental to this issue and cannot be brushed over by saying that it's the woman's fault for making bad choices.
The reality is that nurturing young children requires an instinctive understanding of their needs and a willingness to put those needs above your own. The majority of men, even the "good ones", are incapable or unwilling to commit to that on a sustained basis. Hence the woman ends up being the default parent, because she knows that the man won't step up and she's not prepared to see her children suffer as a result.
The majority of women would not want to place their baby in full time childcare 10 hours a day, 5 days a week the minute her maternity leave is up. If the man refuses to flex their own job to avoid this, then the woman will feel they have no choice but to reduce their hours for the benefit of their child.
Also, many men refuse to recognise childcare as a family expense, and so when a woman does the maths, working is often more expensive than staying at home.
Until men take the responsibility of fatherhood as seriously as women take motherhood, women will be at risk of being shafted. And I'm not talking about martyring themselves to their children here, I'm talking about meeting their children's needs and doing what is best for the family.