Is it normal for us adults to not accept sorry as easy as kids do?

When it's kids they brush it off...well sometimes they don't always accept it.
For us adults it's seems that we have a difficult time accepting "sorry". My dad hates thay word...when people hurt others or him badly. He doesn't believe in that word.
When a teacher called out a student for saying hurtful things to his friend and backstabbing. That student said sorry so may times. The victim said, "That's okay." I said, "No, it's NOT okay. HE betrayed you, he said hurtful things over again. True friends don't do that." Then I told the bully that sorry doesn't always do any good. He kept saying sorry but we ignored it. I also seem to have a harder time accepting sorry than I did as a kid.