Over the years I've seen a large volume of creative software, often free, that is used to produce output, that requires, as part of its license, that you give the creator of the software a cut if you sell any of the things you make with it.

This includes everything that is "free for non-commercial use", such as, if I recall correctly, Blender (in the past), most of the Free Fonts out there, and a lot of free software.

Edit to add: This means everything under the CC BY-NC-SA 3.0 license. There is a huge amount of content distributed this way.
http://creativecommons.org/licenses/by-nc-sa/3.0/

The iBooks Author Software is an Apple provided development tool specifically for the purpose of creating iBooks for the iBookstore.

You can give your books away free in the iBookstore, and you can also, as you note, output the results in a variety of formats not suitable for the iBookstore. Those are a nice bonus.

Sometimes I get the impression that people think that everything should be free, for any use, and that the people who create these free things should have no right (or that its "audacious" to exercise some right) over what terms on which they distribute these free tools they create. (Or maybe only the "right" to distribute them on terms you agree with.)

Apple is providing a free tool, and the restrictions that come with it are the cost. Either the value of that tool to me exceeds the cost, or it doesn't. (and the "glovebox" example is nonsense, the EULA is part of the Mac AppStore sales process, you could read t before downloading the app.)

It is the same way with the Free Software Foundation. If they made a tool called "ePub Author" and that tool-- especially if it included templates and copyrighted imagery and other work, as iBooks Author does-- required you to license any works created with the tool under the GPL, then I'd make the same evaluation- is that restriction a cost that exceeds the value of the tool or not?

If you don't like the EULA, feel free not to use iBooks Author and use whatever tool you like that's value proposition is one you prefer. To rail against Apple for providing this tool seems to imply that you feel they owe you something.

Very often today we've seen Apple offer all kinds of new and innovative things, and I've seen a content stream of comments along the lines of "these are bad because apple profits from them". Of course Apple profits. We all profit, though, because they changed the economics of the education situation. If you want something different, create it.

We're not entitled to demand people to produce things for our benefit in ways we dictate, at no possible benefit to themselves.

UPDATE:

Further points:

1. iBooks produced by the iBook Author software contain with in them Apple copyrighted code, both javascript and HTML, and thus are derivative works. It is not just images and layout. Since every open source or GPL project imposes restrictions on derivative software, it seems reasonable for Apple to do so as well.

2. Imagine if this product had been released to ONLY support iBooks in a proprietary format. Apple released a tool last year called iAd producer. This produced ads but only for the iAd network. It is completely proprietary. Nobody complained.

Would those who think these terms are unreasonable have complained if Apple hadn't included the ability to output in a standard ePub format, and the ability to distribute derivative works for free?

Is it really the case that making this tool more restrictive by limiting its interoperability would have removed these complaints? If not, how can you complain about Apple producing a tool to support their proprietary book format? Is Apple required to make all software capable of supporting whatever you want to do with it ? Should Xcode be require to produce Android apps?