Apple's sense of what's appropriate can be funny (or frustrating), at least when it comes to games.
When I developed a WW2 game for iPhone, they called me and told me to remove references to Hitler, Stalin, and to remove the phrase "dirty communists" from one of the (German) mission briefings.
Such things are "not appropriate" in the "context of the App Store."
Violence and profane language is fine. Politics, religion, and sex are taboo, or at least open to an undefined and sometimes contradictory sense of "inappropriate" or "offensive."
Middle east war games are difficult to get through as well, you can't have entities like "Iraq" or "Afghanistan," instead you have to make up countries like "Zahrastan" or such. A game that actually takes place in Iraq or Afghanistan would be too "political."
But there seems to be quite an element of luck as well, lots of things get approved despite violating their rules, and lots of things get rejected for seemingly bizarre interpretations of their rules.