Here is the truth about Ubisoft and the Wii U. Zombie U was one of the most financially successful Wii U titles, and for a launch title, most developers/publishers, can only dream about selling the amount of units that it sold on a Nintendo console. The issue is they developed it twice. It was originally Killer Freaks and they change it around. This cost them big money and that is their fault.
As for Rayman Legends, Ubisoft had a near monopoly on Wii U in early 2013. Had they released it on the Wii U exclusively they would have had no threat from either first or third party Wii U games for atleast six months. This would have entailed a large cash infusion into Ubisoft's bank account. Instead, they chose to wait six months and turn the game out to die against the behemoth that is Grand Theft Auto V. The fact that it sold best on Wii U tells me they should have made it remain a Wii U exclusive earlier in the year.
Splinter Cell Black List, while a good game, showed that the series is basically Ubisoft's version of Resident Evil. Many fans were divided as to the quality of the titles and the direction of the series. In the end it sold abysmally, however, it sold best on Wii U. Yet Ubisoft gimps the Wii U version when it should have been an exclusive from the begining.