Children have to attach to their caregivers in order to survive, even if the caregivers are abusive. Victims of kidnapping and hostage-taking also develop some attachment to the people who hold them hostage and often defend the kidnappers. This is because their survival depended on those people, and that attachment helped them to survive. If you grew up with abusive people, you probably associated a lot of the dynamics of those relationships with being cared for. That is why survivors are often attracted to new people who treat them similarly.

Also, nobody is all bad or all good. In relationships with people who "are not good for you," not everything they do is harmful. You can ask yourself what you are getting out of those relationships, as well as how you might be getting hurt in those relationships. What is familiar might feel comfortable, and it might even feel very strange and hard to tolerate when someone treats you with genuine concern if it is different from what you are used to. What is familiar at least feels somewhat predictable and might give you some sense of control.