We shouldn't forget that hobbyist programmers can write and test apps without paying the $99 fee. The tools are freely downloadable.
"You can learn how to develop apps for Apple platforms for free without enrolling. With just an Apple ID, you can access Xcode, software downloads, documentation, sample code, forums, and Feedback Assistant, as well as test your apps on devices. If you don’t already have an Apple ID, you can create one now. To distribute apps, join the Apple Developer Program."
But they won't. Nobody wants to work on something that they know they have no chance of sharing with their friends without paying a (for them, in that point of their life) significant sum of money for that privilege.
"You can learn how to develop apps for Apple platforms for free without enrolling. With just an Apple ID, you can access Xcode, software downloads, documentation, sample code, forums, and Feedback Assistant, as well as test your apps on devices. If you don’t already have an Apple ID, you can create one now. To distribute apps, join the Apple Developer Program."
https://developer.apple.com/support/compare-memberships
So the poor hobbyist argument is really a moot point if the point is writing apps for yourself and to learn.