There's not much of an excuse for not releasing Destiny on Wii U. It's just as powerful as the other two platforms Destiny is on - PS3 and Xbox 360. It would cost nearly nothing to port the PS360 version to Wii U. It almost looks like they have a personal vendetta against Nintendo just based on that even though it's (probably) not true.
With the Destiny hyperdrive roaring towards its September release date, Activision and Bungie have been revealing lots of information recently. The beta test for both of Sony’s PlayStation systems will arrive on July 17, while Xbox 360 and Xbox One owners will have to wait one full week more to get their hands on the sci-fi FPS. Beta access is only available via pre-order, and will end on all systems on the 27th.
The obvious omission from the list (aside from the PC) is Nintendo’s Wii U, which has been shunned by many developers entirely. A motivated group of fans known as “The Guardians” have hijacked Change.org and launched a petition to bring Destiny to the Wii U. The group hopes that if enough Wii U owners sign up, Activision and Bungie will take note, and hopefully adapt the game for the console. Given that the game is coming to previous generation consoles, and the Wii U has seen a sales spurt thanks to Mario Kart 8, their list of excuses seems to be narrowing. That said, any work to port the game would mean it’s release would most likely be a year after the game goes on sale for every other platform on September 9. Still, there can be little harm in Nintendo fans vocally encouraging third party developers to take note of their growing presence.
After all, it worked for Operation Rainfall.