Still, Die Hard has a redemptive arc for its hero, not dissimilar from other great Christmas stories. Like Ebenezer Scrooge in A Christmas Carol, John McClane finds his Christmas Eve interrupted by uninvited visitors, and due to their intervention, he learns to be a less selfish person. Both characters' epiphanies come when they're forced to confront their mortality. Scrooge repents at the site of his future gravestone, and McClane realizes he owes his wife Holly an apology while picking shards of broken glass out of his feet.
20th Century Fox
So if Die Hard is set at Christmas and explores similar themes to classic Christmas tales, why is this a thing people are even talking about? Well, for one thing, Die Hard wasn't released at Christmas. It was a summer blockbuster, hitting theaters in July 1988. All that Christmas business was merely a function of the plot, not a selling point of the movie. Most of the Christmas movies we love were actually released during the holiday season. But not all.
For example, despite the fact that Miracle On 34th Street is literally about a guy claiming to be Santa Claus, it was released in May. Why? Because the head of 20th Century Fox thought it would make more money in the summertime. This strategy involved making the Kris Kringle character as tiny as possible on the poster, and releasing an intentionally vague trailer that didn't actually feature any footage from the movie itself. So how did Miracle On 34th Street go from a hit summer comedy to a Christmas classic? In December of the same year, the stars reunited for a radio adaptation. Then again the following year. Made-for-TV remakes popped up in the '50s and '70s, all releasing at Christmastime.