Why do people promote violence?

Why do people see violence as okay and promote it on their kids?

I am aware and understand that many people who are not violent people have fought a few times in their life when a situation is very severe and even though it probably still isn’t right, it can be understandable. But overall, why do people accept violence?
Updates
+1 y
This does not include self defense.
Why do people promote violence?
Post Opinion