Superchunk, time to dispel the second aspect of your self-fulfilling prophecy theory.
You mentioned that the HD market sustains sales of core games because 3rd parties created that market.
Now look at two games that cater to that market, one that came out on Wii, the other that came out on the twins. We would expect the launch-window sales to rival the launch-window sales of core market games on other platforms. In this case, let's compare Red Steel to Gears of War.
One ended up selling .5million, the other sold roughly 6m. I'll let you guess which sold what on which platform.
Fast forward a few years.
If your theory were true, here is what I would expect of their sequels. Red Steel stays flat while Gears goes radically up.
Instead, both stay at the same levels. This happens also with Assassin's Creed vs No More Heroes.







