I’m surprised by the fuss about Apple’s iBooks Author licensing terms. The terms prevent you from selling your iBooks Author-created works outside of the iBooks Store (although they can be distributed for free). You can still export and repurpose the content therein, but you can’t sell the complete, packaged layout file created by iBooks Author in another store.
This seems perfectly reasonable to me, for three reasons.
1) It’s called iBooks Author
The clue’s in the name. It creates iBooks for iBooks. Not generic ePubs for general distribution; specific iBooks for iBooks.
2) The files won’t work elsewhere anyway
The ePub-based output of iBooks Author uses custom CSS and object elements to create the advanced functionality needed for Apple’s textbook format. This shouldn’t be a surprise; Apple has gone over and beyond what’s possible with the current ePub standard in order to make this kind of functionality possible in iBooks. As a result, the output of iBooks Author won’t work in other ePub readers anyway. This isn’t bad; it’s just a choice you as an author need to make – whether to create a lowest-common-denominator reflowable-text ePub, or to develop a fully-functional textbook for a fixed-spec platform.
3) It’s free
Apple have spent many hours creating a free and fully-featured authoring tool to support their store. You don’t have to pay for it. It’s free. Why should they then support competing stores (who could perhaps reverse-engineer and support their ePub extensions), who haven’t paid to create and support the tool?
Apple provide a comparative tool for us iOS developers, called Xcode. This is the free development tool used to create iOS and Mac apps. Our Xcode-authored iOS apps don’t run on other platforms, and even if they could, I would fully expect Apple to prevent us from selling them in competing stores. That’s entirely reasonable in return for free tools and a profitable store ecosystem in which we can sell our work.