Welcome back ladies and gentlemen of the internet. It doesn't take much for family tensions to rise. In the heat of the moment, people may say things they don't mean, or even act cruelly towards one another. There's never an excuse for abandonment; children need their parents, and leaving them is one of the most traumatic and selfish things a person can do in this life.
That brings us to the Reddit thread. The original poster (OP) is a woman whose mother abandoned her as a girl. Being raised by her father, she had no relationship with her mother for most of her life, and that suited her. This is until her mother desperately reaches out and tries to make amends, claiming she wants to get to know her grandchildren. The woman holds firm, denying her mother the courtesy of meeting her own grandchildren. I think the punishment fits the crime.