Why is the "it happened to me and I'm ok" excuse used to justify certain behaviors?

I know people who were actually abused and removed from their parents by the state and still love their parents and were very close with them even after being removed from the home. The children say they were ok, and turned out ok so everything is fine now.

I know wives who were beat by their husbands or husbands who were beat by their wives and still love them and stay with them.

Having a close relationship with someone who hits on any level isn't indicative of a healthy relationship. This means anyone, at any age, in anyway. So why is this used as a justification?