Fandoms
People love Home Alone.
And seriously: what's not to like?
We see a famous child star systematically destroying two grown men, all in the service of saving Christmas—naturally, both American and international audiences ate that up, even if critics spit it out (Home Alone has a weirdly low Rotten Tomatoes rating for such a popular movie—only 55% of its critical reviews were positive). (Source)
Critics aside, the movie's popularity hasn't flagged in the decades since its release. Although Macaulay Culkin now performs in a weird indie band that does pizza-themed parodies of Velvet Underground songs, his defining movie remains a perennial People's Choice, shown frequently on TV in between Thanksgiving and Christmas.
Even George from Seinfeld had a moment of emotional catharsis watching Home Alone. He cries after viewing it, explaining, "The old man got to me." The fact that Marley turns out to be good (which you can easily guess at the beginning) adds an element of feeling to what would otherwise be a movie focused on zany slapstick—and it cracks through to George Constanza's soul.
So, the movie has fans a-plenty. If it didn't have 'em by the thousands, how could it have spawned a sequel like Home Alone 2: Lost in New York, with the return of most of the original cast? Or fansites (like this one) exclusively devoted to Home Alone-mania?