I don't see why this is such a surprise. Ubisoft have been the most willing publisher on both Wii and WiiU, have successfully marketed their games and have sold a decent enough number of titles to justify releasing more. The early months of a consoles are about building a customer base for the future and Ubisoft are the only third-party publisher that have had any measurable success in this (ZombiU).
Ubisoft- Initial success- continued support
EA & Activision- Poor initial sales- reduced support








