You're mistaken! Cheat codes only don't work in multiplayer. As for my opinion about cheat codes: using them makes the game monotonous and uninteresting!
Here, it's more a matter of taste - besides, it's important to know what goals the player is pursuing in the game. For example, if he's interested in watching video clips, he can achieve his goal in the shortest possible time using cheat codes, without unnecessary and monotonous routine.
