Last year a the owner of Dwayne's Photo, the only lab in the world that still processes Kodachrome, noted "If Kodak doesn't feel it's economical, they might stop making the film itself … if film volumes become so small that we're unable to economically process it, then we might stop."
From Kodak's press release:
Sales of KODACHROME Film, which became the world’s first commercially successful color film in 1935, have declined dramatically in recent years as photographers turned to newer KODAK Films or to the digital imaging technologies that Kodak pioneered. Today, KODACHROME Film represents just a fraction of one percent of Kodak’s total sales of still-picture films.
“KODACHROME Film is an iconic product and a testament to Kodak’s long and continuing leadership in imaging technology,” said Mary Jane Hellyar, President of Kodak’s Film, Photofinishing and Entertainment Group. "It was certainly a difficult decision to retire it, given its rich history. However, the majority of today's photographers have voiced their preference to capture images with newer technology – both film and digital. Kodak remains committed to providing the highest-performing products – both film and digital – to meet those needs."