"I always thought that the Wii U and Vita would be great targets for Doom 3: BFG Edition," Carmack explained. "We should be able to bring that over directly, but [the platforms have] generated nothing for us on the publishing side of things, because they're somewhat marginalized platforms."
"Clearly there's a difference on the handheld platforms," Carmack continued. "While the 3DS is doing okay, the Vita's really not doing particularly well."
"A lot of that has to come from the fact that [...] everybody is carrying a pretty good gaming platform already, and selling a new one to them is a little bit of a harder sell," Carmack said, referring to the widespread adoption of smartphones.
"I'd love to be able to develop on the 3DS and some of the other small platforms," Carmack said. "I'd like to see the games show up on the Vita or the Wii U, just to play with some of the characteristics they've got there, but it's extremely unlikely to happen. There's a finite amount of time and only so many things we can focus on."