The fundamental issue that most markets have the Wii U... lack of sales grabbing games.
Mario as a brand is pretty weak in Europe compared to other places, along with the fact that as others have stated Sony has a stronger grip there and for a while longer. Nintendo just dropping a new system with just some ports, a Mario game, a party game and a Zombie FPS game is not going to cut it. I have no idea how they are promoting their games and the system but Nintendo really just needs to find a game or property to grab the European and North American audiences to get better sales and build a stronger culture in the territories where they have problems.
If they didn't seem to have such bad blood with Konami and EA, a Wii U soccer game would be perfect. Instead Nintendo might just have to make one themselves although it can't be another Mario themed one.