Those aren't fair comparisons though, the stores themselves are more akin to your examples than the developers selling through them.
But it's actually worse, if you're a musician you can sell your music through a label or you can sell it on your own. If you are a mobile developer you can sell through one of the app stores or you can pound sand.
"the stores themselves are more akin to your examples than the developers selling through them."
How so? Game publishers sell their products through iTunes – book/magazine publishers, movie studios, and record labels do too. The game publisher invests and curates, Apple acts as distributor and retailer – that's the same as how other media work.
"If you are a mobile developer you can sell through one of the app stores or you can pound sand."
Or the third option: you can work for one of the successful software publishers. We now know there are at least 25.
Writers don't have to pretend to be publishers. Recording artists don't have to run a record label. Mobile developers don't have to be software publishers or distributors.
That's like saying you can get a big 3 record contract or become a studio musician. As long as you're playing music right? My point is just that comparing the disparity in the app stores to the disparity in other media verticals is not a good one.
But it's actually worse, if you're a musician you can sell your music through a label or you can sell it on your own. If you are a mobile developer you can sell through one of the app stores or you can pound sand.