Yeah, it's a good observation. I actually read a book right in the aftermath of my traumatic venture with my last therapist. It's called "The Betrayal Bond" by Patrick Carnes. It talks about what you call a "negative bonding", which I'd rather call a "trauma bonding", but it doesn't refer to therapy specifically. It just describes our general human tendency to get into relationships that turn out to be exploitative and end up traumatizing us because we always attempt to "resolve" the original traumatic experience with primary caretakers, but we do it through other people. We are driven by the need to "repair" the original relationship in order to keep the bond that once was super important for our survival. But, since we often can't repair it with the original characters, we use other characters.