[antalbud]

I don't really see the problem. This is not a word processor, this is - as the name suggests - a software which lets you create interactive eBooks in a proprietary format which is only compatible with the iPad.

It is its sole purpose.

Apple as a publisher provides you this software for free specifically to help you publish on their own store. And they restrict you to use it only for that. They don't own your content.

You can create ePub documents with Pages (for example), which are readable with any ebook reader, and you are not limited in any way in how you choose to distribute them.

I don't think this is comparable to restricting the use of a Word or PDF document.