It's sad really. Those kids are getting abused. Perhaps not physically but certainly by neglect. They'll never be normal behaving social human beings because you need proper attention and good rolemodels to become one. On top of that they are probably disliked by a lot which will do no good for their selfimage causing again a lot of unwanted behaviour.
Some people should never have kids, they're just not fit to be a parent. But history will repeat and those not properly raised kids will have kids of their own and probably make the same mistakes.