Most people, when beaten or intimidated by someone in their own family, feel helpless, afraid, embarrassed, and guilty. These emotions, plus the belief that what happened was not really a crime, often keeps victims from taking any action. Everyone hopes it won't happen again.
Why bother to have someone arrested?
It lets the abuser know that violence will not be tolerated
It gives you, as a victim, some control over the situation
It allows the court to mandate treatment for the abuser
It can allow the court to issue a No Contact Order for you and your family