The Wii U
This entry is not about the Wii U in and of itself. The console existing was not a strange decision or mistake. Rather, it is about the name. Nintendo going with "Wii U" as the name of the Wii's successor was a very strange decision. It was confusing and didn't do a good job of explaining what the console was trying to do or what set it apart. It made it sound like a Wii update or add-on, rather than a whole new system. It was just an odd choice, and Nintendo paid for it.