It's official. Yves is talking out of his rear end.
If "mature" games don't sell on the Wii U, can he explain how ZombiU has sold nearly double the next best-selling game from the company on the console?
It seems fairly obvious to me. ZombiU and Rayman Legends are the biggest selling games the company has put on the console. It's got nothing to do with the games being "mature", it's a question of them being good games that suit Wii U's uniqueness. I'm not remotely surprised the AC games haven't been huge sellers on the console, given that the series skipped Nintendo consoles for years and the Wii U versions had zero marketing to make sure people knew they existed. I imagine Watch Dogs will suffer an even worse fate since it's coming months after the other versions, and without some of the online features.
If Ubisoft's games aren't selling on a Nintendo console, that's Ubi's fault.