But that label seems to be falling by the wayside as the film piles on awards and heads for the top of the box office,
He says "Brokeback" was considered a major financial risk, but has raked in close to $45 million dollars so far, more than triple its modest budget.
And what's most surprising, Cagle observes, is who's driving the film's ever-growing popularity.
"Brokeback" is the story of a doomed love affair between two Wyoming cowboys.
Star Heath Ledger was drawn to the role despite the film's sensitive subject matter because "the story was so heavy and beautiful, and (because of) the opportunity to investigate this character, this incredibly complex figure."
After winning four Golden Globes last week, including best drama, "Brokeback Mountain" ticket sales soared.
You might think big cities are driving the film's success, but it goes much deeper than that, Cagle notes.
"What's driving the astonishing grosses for this movie," says Focus Features Co-President James Schamus, "is the numbers coming out of places like Little Rock (Ark.) and Billings, Mont. and Salt Lake City and Columbus (Ohio) and Pittsburgh. The film is doing business in every corner of America."
City slickers and country dwellers alike are lining up for "Brokeback," despite concerns that some moviegoers would shun the film because of its untraditional theme.
Now, it's arguably become the country's hottest date movie, Cagle says.
"It has become," Schamus says, "officially uncool as a guy to say 'No' to your girlfriend to this movie. It's something that you're now in a zone where, if you say 'No,' you just don't look that cool anymore."
Cagle concurs: "It's being driven by women. Men will not seek out a love story," whether heterosexual or homosexual, "but they will go with their wives and girlfriends, and that's what's happening here."
Moviegoers questioned by The Early Show also agree.