Yes, I know that Apple removed pornographic and political apps from their App Store. It's their store, curated by their staff, running on their servers. I will admit it would have been courteous to have outlined a full set of ToC's before the developers spent time writing their apps (an especially shitty situation since devs have to pay $100 a year to get into the App Store, although Xcode is now a free download) but Apple have apologised for that now, and admit their curation standards are a work-in-progress. It's not a complete answer, but things have progressed beyond the sensational to the mundane.
Anyway, iOS users aren't really denied access to the content you mention, are they? They can still open Safari and browse to whatever they choose. Porn and political japery are mere taps away. You can even fire-up YouTube and watch video replays of RMS eating his own toe-jam in front of dozens of fellow free-software advocates. It's just that Apple offer a curated alternative. It's like apt-get, except with a nice GUI and a bunch of people who try to ensure no malware gets through.
Don't insist that everyone offering goods in a free-market should be forced to follow your ideals -- it smacks of the totalitarian. If what Apple is doing is wrong the people will vote with their feet and go elsewhere. So far, it looks like the iPad's drought of pornographic and political cartoon apps aren't really hurting the user-satisfaction surveys. Or Apple's bank-balance.