I never thought it was a secret what Canon was doing. Clearly it makes more sense to break up the functions of the cameras from a business standpoint, especially when they share much of the same technology. Why would Canon release the perfect camera for everyone? If they did it would cost a bazillion dollars and no one would buy it. This way, they aren't as expensive, there are models for many different price brackets, and it forces people to buy multiple.
The 5Diii seems like the perfect all around event camera: great pics in low light/high iso, FF, quick, great focus system, amazing video, perfect (debatable) MP for events, etc.
If I want pics of wildlife I will take out my 50D (crop) for the extra "reach" with my lenses. And believe me that is some serious extra reach. My 100-400 is like 160-640 on the 50D!!!
If they made the 5D with a bazillion pixels I wouldn't need a crop body. I would sell it and buy the 5D. That used sale wouldn't be money for Canon and they realize that. Having different models for different uses is a great business idea, as long as they share parts and technology in order to keep costs down through economies of scale.