That's an interesting point about the career-focused people which I hadn't observed before. I'll need to consider, but that seems as much a function of 80's genre movies in general (the greedy executive or real estate developer is a Hallmark of almost any 80's movie set in a city).

I'll die on the hill, though, that the John/Holly relationship is not really a theme in Die Hard. It's a plot driver, sure, but I see no evidence that the movie actually cares about it. Holly and John have a single scene together before the shooting starts (which I believe is there primarily so Holly can storm off and leave John alone making fists with his toes, because the plot requires it). They spend the whole movie separated, don't speak, and barely talk "about* each other. We know spend more time talking about why Al isn't a detective than why John and Holly's marriage didn't work. Then they kiss at the end, because that's what action heroes do.

Finally, I love the idea of Argyle being motivated by anything. He's a walking plot contrivance (I enjoy the actor, though).