Thank you for sharing that, it's really good to see another angle on the problem that I have been thinking about and especially one that is so well stated.
I personally start to feel suspicious that I might be attributing too much responsibility when in situations like the ones that you have described, you can blame the parent, but also the parent's parent for the damage that is done to a child. In a way it feels like you end up attributing double the amount of responsibility.
Perhaps a more simple example, that I have been thinking about a lot, is passing on Covid. If one person passes it onto another, who passes it on to someone who dies of it, are they both fully responsible for the death? Is the responsibility split evenly? Or are neither responsible?
More related to your examples, I would generally not blame someone for the way they act if it is clearly a result of their upbringing or genetic factors, but surely everything that I do could be attributed to my upbringing and environment as well, so I then struggle to understand how to blame anyone for anything.
It's a very interesting and important topic, but not one that I have been able to come to any sort of conclusion on.