They haven't said it outright, but from everything I've heard from other indie devs, this move was predicated by Microsoft's asinine publishing requirements. While they could have tried to stay independent on other platforms, Ubisoft probably pushed hard to get rights to publishing on all platforms. It means the devs will lose a cut, but hopefully they will gain some resources for QA and the like by working with Ubisoft, in addition to access to XBLA. Given the state of Wii U, I can't blame them for trying to get a wider audience.
In regards to Kickstarter, I backed them for their ideas, in addition to Wii U support, so maybe my investment was of a different sort than some.