I'm someone who believes strongly in parental influence on their children but I still think this is a bit simplistic.
Yes, ND children often get parented in a way that is less effective. Because the parents don't know any better, are overwhelmed as often as becuse they think children should just behave differently. Ditto, good kids can go bad with poor parental decisions which may be made for any number of reasons. But at the same time, there are other factors - outside influence, natural personality of the child, school, friends, abuse etc.
we have a chld in our broader family. There is no question that he is very difficutl to parent. It's also an unfortunate truth that his parents are both fairly ineffective and both are constantly bemused by the fact that he doesn't behave the way they think he should. He's ND but it has taken until he's almost a teen for that to be confirmed because his parents were first in denial and then when they decided they did need support, they're overwhelmed and stressed and it took them 4 years to get any sort of diagnosis. The relationship between his parents is also poor and his father in particular has a lot of issues which have impacted him including regularly disappearing for months at a time. Plus Covid was bad for veryone, but I suspect his experience was worse. His parents weren't great about getting him out and about pre-Covid, needless to say, during Covid he was just at home, all day, every day.
His mum wants the best for him and is doing her best, but she doesn't have the support of a decent partner and her own issues mean she hasnt listened to school or other professionals. Any feedback given to or about him she pushes back on aggressively, I suspect becaus she felt as a child that her parents NEVER supported he (from what I can tell, that's not untrue).
It's not as simple as, "parents don't care or put the effort in". Even when parents are makign the mistakes, it's not a simple, "they're not trying hard enough".