You know if Pikmin 3 was a shooter... it would have released right on time. Same for The Wonderful 101 which didn't even get an official game title until I think right near the launch window it was supposed to be a part of.
New game designs or unique game designs looking to evolve with new ideas... plus first time Nintendo getting their hands wet with HD graphics, taking online more seriously, doing Miiverse integrated stuff. All of that takes more time. There is also the issue where some of these games are designed well to work with Wiimote + Nunchuk and now they are turning back to a Gamepad as the primary controller for players. There is tons of stuff to figure out.
I am fine with waiting as long as Nintendo takes to make any of their games because the result is 90% of the time just fresh and awesome. Those fresh game designs compared to all the too-similar 3rd party volume of game releases (shooters and racers and rpgs) don't offer that same level of gaming bliss.
It takes a game on the level of Tomb Raider to really surprise me and keep me engaged the whole length of game from third parties, while Nintendo manages to surprise and engage with relatively simple games like New Super Mario Bros U or Nintendo Land or Fire Emblem, just to name a few of the more recent ones.
