Your error is assuming developers are entitled to use Apple's IP to make money. They're not.
If you are using someone else's property to make money, and they ask to be compensated for use of that property, then you need to pay them for that use or not use it. It doesn't matter that someone else gets it for free, or that you'd make less money. If you don't agree with their terms, then you need to decide what is more important to you and act accordingly.
They're not mandated to only sell in the mall. They can sell in the mall across the street, at the store next door, or online. But if they want access to the mall's customers, using the mall's property, then they need to pay the mall if the mall asks. They're not entitled to use the mall's property just because that's where most people in the town shop.