Its a way more complicated issue than just, "why did you choose to have babies with a man like this?" And I think the fact that so often people don't see that, makes the problem worse because all the issues aren't being addressed.
As a society, we still see women as the primary caregivers. Men who DO shoulder their share of the load get disproportionate amounts of praise. Women who ask their husbands to do more are often fighting not just his own resistance, but resistance of the people around them - their families, extended social group etc. A woman who resents that she has done 100% of the nights will get dozens of people saying, "ooh, but he has to work doesn't he?" or "well, at least you're not a single mother" or "well, your husband is at least good at nappy changes and taking the kids on a weekend for a few hours, mine can't even do that."
So even knowing that it's not right and that she's on her knees, it's hard for many women to really truly deeply know it because the messages she's getting all around her are that it's normal or that she has no right to complain.
And of course, on top of that, it might be that he is, in her mind, great in other ways. And she loves him, wants to be with him etc etc. Or she gets caught in a cycle of, "well, he does bring in 80% of the money so really, I can't complain" or, worse, "he brings in 80% of th money so even if this doesn't work for me, what options do I have?"
Endlessly, on a loop.
Changing things is far more complex than just saying an individual woman should somehow just KNOW that her DH was going to be shit or that when he is shit she should somehow force him to be better. Because again, that relies on the man thinking that he needs to be better. My DH is amazing. He's been a SAHD etc. But over the years he still had to be reminded surprisingly often that I wasn't the default parent. Socialisation and all the rest just meant this wasn't' instinctive to him. But because he's intelligent and fair, he listened and adapted accordingly. But not all men are able or willing to do that.