Exactly this, Apple wants to get paid for services they did not perform. Yes they need to be compensated for running the AppStore, this is the develop fees, if they are too low Apple should raise them. Maybe even charge the developer per App download.
Yes Apple needs to be compensated for iOS security, but the user already did that when they bought a $1,000 device.
No, Apple should NOT be compensated when a developer wrote an App that has two tiers of service and I paid them to unlock new features. Nor do they deserve anything because I bought 3000 gems somewhere. If Apple handled the payment than they need to be compensated for payment processing, which is around 1-5%, but nothing above that. And if a third party handled the payment than Apple deserves nothing.