Unfortunately you are right, bad parents exist in all kinds of situations. Don't get me started on foster children. There are some great foster parents and there are the monsters we read about in the press who abuse the foster kids who are in there care.
My own parents divorced when I was very young resulting in my living with a variety relatives until I was almost 9 years old. My mom and stepfather stayed together until my stepfather died 30 years later. This didn't stop them from fighting violently, often to the point where the police were called. We three kids were never abused though. Rather than resent my sisters, I embraced the freedom their being the focus of attention provided me. Before they came along, I could not look cross-eyed at someone without being called on it.
The
one thing that might repair society - two good parents - can't be legislated. Any f'n nimrod can make a baby, yet we can't mandate preparation, ability to provide and nourish, obligation to love, guide, educate, discipline, encourage ... nothing. And the worst reproduce the most.
Law just imposes child support and, perhaps, intervention if the kid hasn't eaten in months. Downside of freedom, I guess.