They should be paying developers, yes, but not for the pain of going through review but instead for the simple fact that an iphone without any app developers is almost completely worthless. Apps make their platform more valuable.
The iphone has plenty of app developers even if there isn't a single third party app anywhere. Those app developers just work for Apple instead of a third party. I don't think Apple cares about having a thriving third party app ecosystem.
And that's how you know a platform is obsolete.
Windows Phone, Zune, etc.
It is frustrating that HP got this right with WebOS and still fucked it up. Having a touchpad was a sublime pleasure for a few years.