While I agree with a lot of your points, the one that people never bring up, but is a HUGE factor in achieving financial success on the App Store, is marketing. An alarming rate of indie iOS developers simply program an awesome game, submit it, and wait for it to take off.... uh, lol. They think there's some kind of magic protocol that gets users' eyes in front of their product, just because it's now searchable on an enormous shelf of software.
iOS developers simply don't budget for real, aggressive marketing. They might hit reddit, or forums, or make some YouTube videos that they try to get viral, but they don't throw real dollars into an advertising machine. Quite frankly, the App Store is like any other over-populated storefront: you need to thoroughly market your product in order to stand out from the crowd. I don't care how awesome your game or idea is.
And this is one of the biggest problems that (dare I say) most iOS developers just don't seem to understand.