Why Are We Enabling Abusers?

I'm sure everyone is familiar with that quote "Everyone is fighting a battle you know nothing about."  It's been applied in everything from discussing addicts to sex abusers; I'd like to know why children living in those situations are supposed to "be kind" and enable the ADULTS who failed them.  For context, I grew up with an alcoholic father and while I was a very smart child, I wasn't exactly capable of getting a job and my own place to live at 7 years old (when I told my mom she should get a divorce after we had to flee our home from my father while he was in another drunken rage).  This is just one example of where that ethic is not so great when applied to real life. The image is of this infamous quote and is apparently by a Wendy Mass, who obviously was never a child living with a substance abuser or the target of a hate crime (because bigots are also "fighting a battle you know nothing about").