Yes, it is a special Apple thing.
Apple is well-known for stopping people from doing anything they haven't directly authorized, and trying their best to get you to do
everything through iTunes.
I don't love their policy on appstore apps only, the my-way-or-the-highway attitude behind OSX and iOS, although I get that it doesn't bother other people.
Content on the other hand, it is inexcusable when content is locked to certain devices. Apple no longer locks music, but they still lock videos and books, and unlike other companies they are
constantly fighting attempts to unlock it. (And you cannot even download the app on competing smartphones/tablets/PCs.)
You can unlock DRMed Kindle books using the tools and guide here:
http://aprenticealf.wordpress.com
Amazon, Adobe, Kobo & Co. have ther token DRM, which has all been broken, and they don't really care. Apple cares, and changes their methods constantly until the people like alf (or brahms) give up and say "buy from Amazon already!!!".