Yes, a notice is displayed after you've already put a lot of work in, that is exactly what makes it slimy. A conditional fee is still a fee.
> This is no different from the zillions of dual-licensed GPL projects out there that say (roughly) "You're free to use this code in projects that you yourself give away for free, but if you want to sell your application you have to buy a license from us".
This is nothing like that. GPL projects do not hide their terms. And developers are very aware that libraries have terms. It is typical. An exportable document format having terms is not typical.
The user will not anticipate these conditions. This is why I call it a bait-and-switch. A company that prides itself on putting UX first couldn't have done this on accident. Either the product passed through QA without UX concerns being raised, or the concerns were ignored.
It's a slimy, used car salesman approach. Apple is better than this.