Apparently, they’re afraid of their big idea being stolen.
Look, Nintendo have made it clear, multiple times at this point, that the NX won’t just be a simple new console- there’s some hook to it, something new about it that clearly differentiates it from every other gaming platform on the market, and from its own predecessors, the 3DS and Wii U. That will be the reason, according to Nintendo’s legendary Shigeru Miyamoto, that the company won’t talk about the NX just yet.
“In terms of NX, there’s an idea that we’re working on,” Miyamoto said in an interview with the Associated Press. “That’s why we can’t share anything at this point, and I don’t want to comment on the other companies. If it was just a matter of following advancements in technology, things would be coming out a lot quicker.”
So- there is something more to the NX, something that hasn’t somehow leaked yet, something that Nintendo think is big enough to delay the reveal of the NX. We don’t know what it is, but let’s give them the benefit of the doubt, and let them reveal the console on their own time. At the very least, it sounds like third parties are on board with the NX, so whatever the new gimmick is, we probably don’t have to worry about it being unnecessary like the Wii U Gamepad.