I think there is something of a wider social problem that is illustrated with that story. Somewhat distinct from the men fucking off and not helping with their disabled kids.
We've basically normalized casual sexual encounters, with people we fancy but who we'd never consider as good prospects for fatherhood (or even just as a life partner without kids.) The reality is though that pretty much any sexual encounter could potentially lead to a pregnancy. And women are more tied to infants in particular than fathers. Mums are usually already attached before birth, a lot of fathers take a bit of time to grow into fatherhood, it's a different experience.
There are parts of society where it's almost totally normalized for mums and kids (and not uncommonly grandmothers) to be families while the men move around from household to household or live separately. My partner grew up like this and I find it interesting to talk to him about it, he doesn't see fathers as particularly important, well behind mums, sisters, aunts, and even maternal uncles. (I disagree obviously but I can see how he came to this way of thinking, and I think it sadly impacted his relationship with his own kids.)
There are some legitimate reasons we got to this kind of attitude - part was trying not to shame single mums. People also wanted sexual freedoms for women. But in the end I think this has contributed to scenarios where young women don't stop and think about whether men they are involved with are father material, and also where there is a lot less social pressure on men to provide for their kids. In part because we see having a baby or not as fundamentally the woman's choice.
Even where the kids were planned and the were parents married, this attitude bleeds out because we are used to seeing it, and also don't usually know what led to other people's situation, so we reserve judgement.