Hasn't everyone always known and accepted (to a degree) that Apple control what goes in the App Store and that their acceptance criteria is organic?
Apple have customers' expectations of the App Store to manage, and like everything those expectations will not be shared by everyone, but Apple still needs to make a decision based on what they perceive is going to be best for Apple and its shareholders.
Don't think Apple decided "Yuk, we don't want this filth in the App Store especially where children might be able to see it", they thought "We don't want our customer base to associate us with this kind of material or it will impact on our brand reputation". As for the continued association with the "softer" material (Playboy, FHM), it's just the same as in newsagents (are they called that in the US?), where these are publications that people are used to seeing there and don't generally tarnish the name of the major newsagent chains that sell them, whereas if that newsagent suddenly started filling a good percentage of their shelves with "Big Jugs Monthly" then the public perception of that newsagent would likely change away from being a friendly family store.
So, it's a business decision, the result of which just happens to be the same as censorship. That doesn't mean it is censorship though. Sure, it's a decision that people will argue against but I think it's one of those "you can keep all of the people happy some of the time..." scenarios. Just look at the opposing postings in this thread and you can see that it was no easy decision.