I’m confused. Isn’t the commission that is paid just a cut of the profits from sales? The 85% not paying commission would be because their app is free. Apple’s argument is that they are providing a huge platform and infrastructure for app developers; many of which are utilizing it for zero cost (except the annual $99 developer fee).

If someone then uses that infrastructure to make money then Apple takes a cut of either 15% or 30% to help sustain the whole thing. Those numbers are argued to be too high although they are basically in-line with the mark-up of most goods and services.

The real complaint is that Apple doesn’t allow alternate app stores that would compete, and theoretically push down the commission to whatever the free market determines is reasonable (and presumably below 15%). Apple, of course, argues that they do it for safety purposes. One way to offer lower commissions is to have less strict screening processes to save money. This could end up being a race to the bottom of quality which may not really benefit users.