Plans for the largest-ever doomsday bunker were just quietly scrapped, and the company behind it has seen a major shift in its clientele after fears of a Mayan-predicted apocalypse blew over in 2012. Robert Vicino, the founder and CEO of privately held Vivos, told CNBC.com that his company has decided to pull the plug on its plans for a 5,000-person bunker in Atchison, Kansas. The project, which received significant fanfare upon its announcement in 2013, would have been the largest publicly disclosed doomsday shelter at more than 2 million square feet. It also boasted an indoor golf course and skateboard park, among other luxury amenities.

Robert Vicino at the entrance to his Terra Vivos underground shelter network. John B. Carnett | Bonnier Corporation | Getty Images

Instead, "with a great deal of energy and expense down the drain," Vicino said he is walking away from the so-called Ark. The company, he explained, incurred hundreds of thousands of dollars in engineering and premarketing costs for the Kansas location, but it still has existent shelters, and will continue to build more. The project, Vicino said, was scrapped for structural reasons: It was to be built in a former limestone mine that had been converted to a government storage facility before Vivos purchased much of it in 2013, but Vicino said he had safety concerns. "I didn't feel safe in there, and I wouldn't put people in there in a disaster situation," he said, adding that the cost to mitigate the structural concerns would have far exceeded the originally predicted $35 million to retrofit the facility. Read More Businesses that cater to doomsdayers

This assertion was strenously denied, however, by Jacque Pregont, president of Atchison's Chamber of Commerce. She laughed aloud when told of Vicino's claim about safety, and said that there are several businesses operating in other parts of the mines, all of which are "very safe." Instead, she said, the Vivos project had difficulty attracting interest. "I think it just didn't work, [Vicino] didn't get the reaction that he thought he would get, he didn't get the interest that he thought he would get," she said. "And that's OK, everybody has ideas that sometimes don't work out."

A diagram of the planned Vivos Survival Shelter and Resort in Kansas The Vivos Group

Vicino stressed that the project was not scrapped because of a lack of buyers, telling CNBC.com he had "hundreds" of reservations for the Atchison facility, but he did admit that bunker interest comes in waves. "It's a funny business: When people want us the most is when we can no longer deliver," he said. "A lot of people sit on the fence. ... When they see something unfolding, that's when they're going to become motivated, but unfortunately for them, it'll be too late." Read MoreHow 'preppers' are gearing up for a US default

Despite these prognostications, interest in bunkers within the preparedness community—or "preppers" as they are often known— is slight at best, said Todd Sepulveda, owner and editor of Prepperwebsite.com. His website, which aggregates and curates discussions and articles related to disaster preparedness, has only ever carried a few pieces on bunkers, he said. Bunkers are more "sensational," he said, and they come with a hefty price tag, and may not be the most important part of preparedness.