Earlier quoted context omitted.
Except Apple/iOS doesn't have the majority market share as MS did. (not that I don't despise this, just stating).
Apple/iTunes has(had?) the dominant marketshare for digital music retail in the USA
The difference with the App Store (full disclosure: I don't think there's anti-trust issues here) is that it's THE ONLY place to buy apps for iOS. There's no place to get a substitute (HTML isn't competitive).
The case against the app store is far more compelling in the one against the iTunes Music Store.