Without getting bogged down in the logistics of each film, the entire point in Die Hard is that they are adult movies with profanity and violence abound. Controversially 5 has received this 12A rating, but why?
It's my son's birthday soon... Amongst other things*, he's asked for the Harry Potter DVD box set. It's his 11th birthday - the very age when Harry Potter discovers that he is a wizard. I hope my son turns out to be a wizard too then maybe I won't have to go shopping anymore. He can just wave a twiggy stick about shouting "DVDidius Box Settiosa" and it will appear. Job done.