I will preface this with it's not going to be for either of us to decide, there are plenty people with plenty more intelligence who have debated this topic, according to Wikipedia: "The difficulty in defining the term and subjectivity of what qualifies as a cult film mirror classificatory disputes about art."

However the general definition according to Google has nothing to do with it's box office success,

"A cult classic is a movie or other work that has a devoted following, but is often not well-known or popular with the mainstream."

Further on,

"The definition of a cult classic can be difficult to define, and there are different interpretations. Some definitions include major studio productions, while others focus on more obscure films. Some definitions also exclude films that have been released by major studios, or that have tried to become cult films. "

So it's open to interpretation, and I'm going to stand by my list, and reinforce the notion that even if they are cult classics there's a good chance someone looking for movies might not have seen some on this list.