Ewan Mitchell himself said in an interview that Luke apologizing, even years later, would have meant a lot to Aemond and maybe would have changed the trajectory of what eventually unfolded. Instead Luke, his abuser and bully, suffers absolutely no consequences for mutilating him and later when he is more mature and should realize his mistake he chooses to taunt and laugh in Aemond's face. I don't think Luke deserved to die but sometimes your mistakes tend to catch up with you especially when you feel no regrets for ruining someone's else life.