Apples and Oranges
Always interesting to see the app stores compared as if they do the same thing.
One does meaningful human audits of every app uploaded ( sometimes to the chagrin of us developers), spending a ton of money on checking there aren't a sea of trojans and other malware infecting the platform. The other does pretty much nothing for the same markup.
I'm sure that both Apple and Google make a ton of money from their app stores, but only one has a plausible security justification for it's monopoly.
Also a bit disgusting to see the proposal that successful businesses should get a discount. The cost of entry and failure rate among mobile apps punish the small players, so further rewarding the most successful players might seem a natural consequence of a competitive app store market place, but the effect on the general app development market place would be extremely pro-monopolistic.
Full Disclosure: I am not an Economist :)