If you want to sell your game on the Humble Store on the other hand, well then they take a 25% cut. That’s the value in being able to deliver a customer.
Apple’s fixed 30% cut is effectively saying: our brand is more important than yours in delivering customers to your App. The imprinteur of being in our App Store and bringing you a customer is worth 30% of your income. Your ability to deliver your own customers is irrelevant; we’re taking 30% either way. Unsurprisingly this sticks in the craw of some companies.
The fact that Apple’s systems make it almost impossible to effectively communicate with your own customer is an even bigger problem for a customer-focused company who’s income & branding depend on a close relationship with their customers: those companies are completely stuffed by the Apple App model & are the reason the App Store has not lead to the explosion of innovation some of us expected - it’s just not possible for a company to sustain themselves outside a very narrow set of income generation patterns.