FSF takes on Apple's App Store over GPL

Correct, usage does not fall under the GPL2, it falls under standard copyright. Apple does not own the copyright so it cannot add terms of usage on software it does not own the copyright to (just as Best Buy may not dictate how you use your copy of MS Windows purchased there). Apple may demand that you add usage terms to your copyright if you desire to distribute your program via their service. But, random users attempting to distribute GPLed software via Apple's service cannot agree to this for other copyright holders.