In an interview with CNBC, Jack McCauley, one of the co-founders of Oculus, said he doesn’t think Facebook can break through to the mainstream audience with VR. McCauley also doubts the viability of a virtual reality gaming market.

McCauley cites issues with people still getting nauseated from the headsets as a significant problem. He also considers the extra cost for the VR equipment as additional issues that separate people from their friends. Many prefer playing standard games on their PC or chosen console with their social group.

“Video games have not evolved into a 3-D experience for a number of reasons,” McCauley said. “I don’t know what kind of application it would be for VR that would keep players plugged in for six hours like they do with game consoles.”

Sales of VR devices have not exactly set the world on fire. McCauley was with Oculus during the development of the DK1 and DK2 models of the Oculus, which sold 70,000 and 150,000 units, respectively. He then left after Facebook bought the company. Since then the Oculus Go has sold 2 million units at a $199 price point, and the Oculus Quest has sold 1.1 million units.

Another issue within the VR market is exclusivity. With such small install bases, it’s challenging to get proper development dollars behind VR games. Many companies want a game to be available only for their device. While the market may turn around, and future developments will push VR into the mainstream, McCauley doesn’t think it will happen.

“I may be wrong, but I’ve been doing this a long time,” McCauley said. “I’ve already done a lot of what people do mistake-wise. You have your gut, and it tells you if you’re right or wrong. And in this case, I think I’m right.”