And if that turns out to be the case, then it doesn't need to be enforced, as people will select accordingly. And then, the people who do want to run things that Apple won't permit in the app store (browsers/emulators/JITs/scripting/etc), or that aren't economically viable with a 30% cut, will have the option of doing so.
The existence of an option does not force you to choose that option.
The existence of an option does not force you to choose that option.