i think this is where your argument falls apart at imo. if we were just talking about the concept of mario saving the princess in every game then you would have a solid point, but since your argument seems(imo) to be about game play then it is not the same as bf, killzone, or forza. the game play in mario games that are not direct sequels have sufficient and visible changes. there is a clear distinct evolution in mario games that goes beyond adding a new board, weapon, or power up. the game play in mario sunshine is not identical to mario 64. the game play in mario galaxy is not identical to mario sunshine etcetera etcetera, while the game play in bf, killzone, dead rising, and forza hasn't since their initial release.
The gameplay in bf killzone dead rising and Forza has changed just as much as Mario.
The gameplay in dead rising 3 is a clear evolution over dead rising one. The same goes for the rest of the games.
In Mario you basically jump and attack to make your way to the end of the level. Each Mario game has added some new strategies/concepts but at the end of the day you are doing the same thing.
Same goes for Forza. There are some new concepts/strategies but ultimately you have the same goal.
And this is exactly what I mean by Mario getting a pass where others don't. Here you guys are trying to make exaggerate the changes to Mario while trying to downplay the changes to the others.