Here's a question - what if the parents are mentally unstable (because they were raised by mentally unstable parents)? What if a large part of society is basically mentally lacking in something necessary to raise kids, but are doing so anyways?
Then how do you fix that?
Serious question btw, and I'm not saying that's what the current situation is, but it's not too far from it and you basically start getting into human-rights when you dictate what they can do reproductively / within the walls of their house when raising kids.
It's also not hyperbole to think that we as a Nation have implemented social programs that have instituted sociological decay, particularly in poor and minority areas. One example was the Housing Act of 1949. Basically, offer subsidized mortgages to home buyers. Take where white people wanted to live (suburbs) and loan them money. Red-line minority neighborhoods to prevent them from borrowing money. Keep rent rates high in that area. Offer federal subsidies to help them with rent. Make one of the qualifications to receive assistance that the occupants must be women and children, no fathers. Have case workers go out and openly recruit occupants for the housing units, and encourage them to have the dad move out for the good of the family, so that the parents and children have decent living arrangements. Watch their family unit turn to crap due to cleaving the household in half.