I am surprised that this is so shocking to the author. Stuff like this is expected and only logical, as wrong as it may be. Apple has been desperately trying to tie people into their eco-system and every move the company makes is a step in that direction whether it may be immediately obvious to other people or not. Also I should mention that I believe Apple is probably not the only company that promotes the use of it…
As someone who is not an iDeveloper and has no idea what the UIPopoverController does: couldn't you make a case that Apple is deliberately crippling the competition and, therefore, make a case for abuse of a dominant position? If it were so it then it wouldn't be about being shocking, expected or logical, but about being against the law.
- Should Apple be forced to open all internal APIs to third party developers?
- Should Apple be offering iPhones with alternative operating systems?
- Should there be an open standard so people can build compatible iPhone clones?
No. iPhone is Apple's product, and they decide how far they will go in opening up their platform.
Third party developers are not fully trusted to do the right thing, and as you can see with Android's malware situation, it's a good thing Apple is not letting random developers do whatever they want.
Since Apple is held responsible by both developers and users to have a reliable product, when they decide to make an API public this is a huge commitment.
Apple has to guarantee said API will be supported in a reasonable way in future OS releases, it has to guarantee to users that calling said API won't result in poor UX or security vulnerabilities.
The situation is much different for Apple's own apps, as Apple can then make the personal guarantee it won't be abusing its own APIs to create poor UX and implement malware.