OP, go on Relationship board and read up a bit. I recommend Stately Homes thread where hopefully you will understand why people go NC, why some people want but can’t and why is it so difficult.
How some people could be so cruel to their family is beyond my understanding,even more so when they are repetitively asked to stop doing it.Then comes the proverbial last straw which sometimes seems very insignificant and Snap!
Abusive behaviour sometimes extends to grandchildren,it causes lots of issues in later life, serious MH problems and wrong life choices sometimesdetrimental to victims.
My father was NC with me, instigated by his DP- her family was on pedestal while mine was told to not keep in touch.His family had to step in and bury him when he died as she couldn’t (not married).
My FIL also has his balls in his darling wife’s handbag, same dynamic applies.Her kids and grandkids are the favourites, ours were an afterthought.
Scapegoat treatment of DH and several episodes of treating him like shit resulted in NC. We didn’t want our kids to come last in the pecking order(even cousins children got better treatment).
NC is not easy but sometimes has to be done to protect the victim from further abuse.
Not everybody has loving and caring parents. It’s very difficult for people with normal upbringing to understand abused person’s POV and very often the trot out the line “you can only have one mother/father”