The history of film has been filled with movies that have failed. Whether it is from low critical reception, weak box office, or a combination of both, many films have come, failed, and then disappeared into obscurity. However, there are a handful of films that suffer from weak reviews/box offices that still live on due to a small yet devoted fan base.
These are called "cult classics" in the film industry due to the small size of their fan base. However, these films' fans are deeply devoted to a film that almost mirrors the devotion given to a cult (hopefully one that doesn't cause violence and theft). These are films that failed to make any real mainstream success but gained a loyal group of super fan; why is that?
Why do some films fail and live on in a small but meaningful way while other films just fail and disappear into obscurity? There are several theories as to why some films become "cult classics", but these are just a few that I have. I am a big fan of many films that could be considered "cult classics" and these are just some of the reasons I have for enjoying them.
One thing a "cult classic" film has to have is some level of film making competence. Even in a film that has a messy screen play, there has to be some level of technical competence that draws audiences to it or a few scenes in a film that are truly great and rise above the films other shortcomings. For example, no one will say that "TRON: Legacy" has the best story or most memorable characters, but it still has a devoted following due to it's unique art direction, soundtrack, and action sequences (you may not remember the story, but you remember the light cycle battle).
Another thing that makes a film a "cult classic" is how unique it is. Prime examples of this would be "Atlantis: The Lost Empire" and "Treasure Planet". Both films were box office bombs and got mixed reviews from critics, but both films now have devoted fans that praise how unique and risky these two films were. These films stood out against the other Disney animated films that were all musicals and followed a familiar and safe formula. These two were action/scifi films in a genre (animation) that has very little of that.
The most important aspect of a "cult classic", however, is ambition. This is what separates "cult classics" and forgotten duds. A movie like "Home on the Range" was bad, but it was bad because it was safe, bland, and pandering to the lowest common denominator. Say what you will about "TRON: Legacy", "Atlantis: The Lost Empire", and "Treasure Planet"; all of these films had ambition and tried to be different.
These films tried to be great and couldn't quite make it, and that's endearing to many film fans. A bad film that's bland and "cookie-cutter" becomes forgotten, because it didn't have the ambition and wasn't unique enough to at least be memorable. There is a sort of artistic purity to films that become "cult classics" and they represent that unique artistic spirit that should never be lost among any art form.