What did he do that was SO bad?
I don’t mean what they were told, but what they actually experienced at the hands of their alienated parent, statistically usually their father.
In my step-children’s case, I know they’d draw a blank. If there had been any abuse, it would long ago have been thrown in our face, written in court documents, crammed down our throat. That never happened.
The children’s only complaints were the visits and visitation didn’t last long enough! The way they ran to their father and flung their arms around his neck told me how much they loved him. The alienation was never their idea, never their choice.