There is an idea, and I will say it is understandable, that there are certain times when it is necessary to hit your child. For instance, when a child runs into the street or when they play with matches. These are circumstances when just talking is not enough and the parent fears for the child's safety, therefore hitting them is an act of love.
The problem arises when parents misuse the idea of fearing for their child; When disrespecting them is a fear, and then frustrating them fears the parent for the child's future. It all gets quite hazy and instead of an act of love it is an act of abuse.
I recall as a child that I thought it was normal, being hit by a parent was the norm. I never knew that others weren't treated the same as me. In my world parents abusing their children was a regular act, something that occurred each day. But then I ventured out, slept over my friends houses and realized that not all parents yelled at their children, that not all parents ridiculed their children, that not all parents hit their children. That it wasn't an act of love, it was abuse. From then on I realized that my life was different then other children my age, I had to stand up for myself and for my siblings. This did not work for my benefit, I was a distraction for him. Offering myself for the sake of the others. Taking him into bed and laying there until he fell asleep. It was difficult, but at that age I knew that it was up to me to try to give the younger ones the childhood that they deserved, the childhood that I did not get to have.