John Hughes used to be an advertising man—so he knew what the people wanted…even before they knew it themselves.
He could write a movie expressing his own real feelings about adolescence—hello, The Breakfast Club—or a movie purely calculated as a hilarious entertainment machine—hello National Lampoon's Christmas Vacation. With Home Alone, he went all in on his less-serious, laugh-oriented side. And he made a lot of money in the process.
Hughes always grasped the idea of having a great logline behind his movies—a sentence or two easily explaining the basic prompt or idea of the movie. In National Lampoon's Vacation, it's "A guy wants to take his family on a trip to a Disneyland-like theme park, but their journey is beset with mishaps." In Baby's Day Out, the logline would be, "A kidnapped baby escapes and makes his way through the big city alone, while being pursued by bungling burglars."
In Home Alone's case, this logline is, "A kid is left home alone by accident for a few days, and has to fend off robbers."
See? You can capture it all in just one pithy sentence.
That's called being "high concept."
While Hughes could get serious and explore actual teenage problems in movies like The Breakfast Club and Pretty in Pink, Home Alone is more of an entertainment machine. It takes a childhood fantasy/fear—"What if I was free from my parents, or even made my family disappear?"—and brings it to life.
The characters Hughes creates are immediately identifiable and endearing—the precocious child, the jerk older brother, the caring mothers, the bumbling robbers. Home Alone isn't necessarily an exercise in dramatic depth as a screenplay…but as a sleek entertainment vehicle, it's got a lot going for it.
And what's wrong with making a ton of money and giving the people what they want? (Not a thing, especially not according to Don Draper.)