It is a lot easier for someone who has not been the victim of domestic violence to say, "well get out", ".I would never stay with someone who didn't treat me right". Part of the abuse starts with the abuser telling their victim how useless they are and how they could never live without them. They threaten them with harming them, their children, their family, etc. They may also say things like, "if you leave me, .I'll call your job and tell them that you______" Then there is the feeling of isolation, it isn't easy to tell someone, even a professional or someone trained in domestic violence about the abuse. People judge, they say they don't, but they do.
Where .I live if you are involved in domestic violence and you are given the opportunity to leave through protection orders, or if an agency who deals with that type of abuse offers to help and you stay, and you continue to have issues associated with the abuse and have children in the home the state will come in and take your children.
Just a couple of months ago about 20 miles from my house, a lady had a fight with her abusive boyfriend, who had a host of other mental issues, she sent her 13 year old to a neighbors house to get help or to just get him out of the house for awhile. The boyfriend shot the boy when he was walking across the field.