Voluntary initiation of relationship. Emotional attachment to captor begins after abuse begins. Love for abuser begins before abuse begins. Can last for decades. Public authorities sympathetic to plight, seeing them as having little control over their situation.
Media coverage generates public sympathy.
All they need to do is leave. Outsiders likely to negotiate for release. Hostages generally released from captivity or rescued by the State. Battered women negotiate with abuser on their behalf and on behalf of their children. Victim must find a way to leave captivity more or less on her own.