Perhaps this is also one of the issues, because they only have to look out for themselves
I think the actual thing is, they CAN only look after themselves. Having a baby costs a lot. My sister has one and she discussed this a lot. Diapers, wipes, food, etc. When one is barely getting by on their own, adding another mouth to feed is out of the question. And it's not like it ends there. There's tuition, their checkups, vaccinations, and medical stuff.