The poor little boy everyone on here is wailing and rending their clothes over would grow up to be one of these "sub human" people you all hate.
So given your wish for them all to be sterilised and wiped out, can you tell me why you consider this such a tragedy? I'm not being goady - there's a tonne of cognitive dissonance and lack of real understanding on this thread, not to mention the horrific othering of Them as though they're a different species which We could never be.
The truth is that any one of us or any one of our children could lose jobs, fall victim to addiction, to a violent relationship etc. Most of us on this thread will have been lucky in that we had stable homes, parents who were invested in us, and who were in turn lucky enough not to have serious mental health issues or addictions.
Families and people like those in the story don't have that. They will have been exposed to drug and alcohol abuse, physical abuse from a young age. Possibly a complete lack of schooling. No support network to turn to, and frankly no idea that could even be a possibility. What chance does a child have growing up in that environment? And when that child grows up and has a child of its own, why would you expect their entire history to magically disappear and them to turn into a stable, switched on parent?
The only way to stop this is to break the cycle by seriously ramping up mental health and addiction services, funding social services properly etc.