But customers don't know that they're buying Nintendo-published games. That's a misconception you always see on message boards and even from publishers. Most people have no clue that Nintendo publishes Wii Fit, Animal Crossing, Zelda, Mario Party, Pokemon Ranger, Wario Ware and Fire Emblem, for example. Yes, even with Smash Bros., which is more of a hardcore game, most consumers have no clue what that game is about, or that it's all characters from one publisher, or whatever. And they don't even know or understand the concept of third parties and publishers, and how that all works. They don't know or care who makes the games. Nintendo just knows how to make a product for a broad consumer base, or appeal to hardcore gamers, or both. Most third parties never wanted to or tried to succeed on Wii, and thought that simply putting any hardcore game on the system (mostly poor or average ones) that it should sell simply because of the install base. At all points, they treated Wii owners like they were stupid, and got the sales that they deserved from it.
(And to clarify, I don't think that a consumer is stupid just because they don't know who made a game. Even most casual consumers can look at a game that we consider shovelware and say that it looks like a dumb game.)