I'm making the opposite of a philosophical argument, I'm making a practical one. Apple is not going to take away the App Store, or make it too difficult for developers to upload apps, since that would be a real threat to their iPhone business.

Developers need Apple, but Apple needs developers too. Currently their market domination makes it an extremely hard collective action problem for developers. Not being on the App Store means losing out on the majority of your revenue, which makes it tough for enough developers to band together against Apple.