I was on board until this part of your post. This is nonsense. Aside from Wind Waker HD and Wii Sports Club (remakes) and the NSMB series (which are, admittedly, very basic in gameplay as a means to hook un-experienced gamers), the rest do offer innovations in the gameplay department.
3D World's cat suit may not be a revelation, but to me, the cherry was. It opened up a lot of new ideas and possibilities, even if it wasn't utilized to it's maximum potential. Dreams of Super Mario 128 came rushing back to the forefront of my mind. I'd love to see a game that takes a similar idea and runs with it, and I don't mean in the direction that Pikmin did.
Wii Fit U offers new experiences with the Balance Board, for better or worse. FWIW, my girlfriend loves the game, and says the new games are fun and use the Board in creative ways.
Game & Wario, much like Nintendo Land (which you are much less harsh on), tries several new gameplay ideas because it is, for all intents and purposes, another glorified tech demo.
I have not played Wii Party U, and thus can't comment on that one.
Pikmin 3's innovation comes from the new Pikmin types. The rock Pikmin and winged Pikmin really open up the gameplay, expanding to a truly three-dimensional experience. Suddenly, your options for exploration, item retrieval, and combat are much more robust, and while the loss of the purple and white Pikmin was tragic, the new types offered up so much more.
Am I saying these are the most innovative gameplay experiences around? No, absolutely not, but to imply that Nintendo simply "plays it safe" with the gameplay of the majority of their games is ludicrous.