That's a fantastic point. Fixing your link: Lewis Galoob Toys, Inc. v. Nintendo of America, Inc. In the same way that Game Genie didn't infringe on Nintendo's copyright, the court should rule that this game modification does not infringe on Blizzard's.
I like to think of it as a variation of Plato's Forms -- the copyrighted product "Starcraft II" exists only as what is on-disk -- a fixed collection of code, art, and everything else that makes up the game. However, once this "ideal" form of the product is loaded into the computer's memory, it becomes a separate and mutable thing. The game itself has become a different and derivative thing simply by executing it, and any number of things can cause that state to be changed. This one single participant of the "Starcraft II" form is ephemeral and isn't being distributed (redistribution being the one reason their suit might be reasonable).
Trust me, I hate people who cheat against others as much as anyone, but this is a much larger issue with far-reaching consequences. Restricting what someone can do with code running on their own computer is a slippery slope, and we have already had enough ignorant court rulings (such as Blizzard v. bnetd). There's also the question of single-player cheating -- should it be illegal for someone to mod their single-player game, to give themselves infinite health, for example?
Blizzard is attempting to rectify a relatively simple technical flaw through the court system, and that's just sad. I hope you're right, AC, that the Game Genie precedent will be upheld.