The majority of the team behind those beautifully rendered pixels you manipulate just jumped ship for EA. This is what happens when a developer’s publisher is greedy, impatient, and demands impractical product turn-around.
This is also, however, a good lesson for the folks at Activision. Games like Call of Duty are not meant to be released every year like Guitar Hero. A few months is not enough time to develop quality virtual environments and thorough plots.