Fundamentally the reason they have that rule is to prevent apps from doing an end run around Apple's 30% cut. For example, to unlock the "Pro" features, go to t

Fundamentally the reason they have that rule is to prevent apps from doing an end run around Apple's 30% cut. For example, to unlock the "Pro" features, go to the developer's website and enter some payment info. The rule has nothing to do with preventing crappy ad-driven experiences. If you had to click 3 ads in app to get 100 gold coins, Apple would be fine with that even though it's crappy - they're fine with it because the action is still happening within their garden walls and if it involves any exchange of real $$ they have enough control to either get their 30% or block the app.