A great point in the article, but IMO this is a function of the screen size, not iOS.
The core problem is reducing the pain of switching apps. On a desktop, screen resolution and space allows you to position windows side-by-side or overlapping. On iOS you have to double-tap, and select an app from the bottom dock to switch to. Android has the same problem- you press the home button, and choose an app to switch to. Both forces the user to focus on managing apps, instead of focusing on the desired "task".
The core problem is reducing the pain of switching apps. On a desktop, screen resolution and space allows you to position windows side-by-side or overlapping. On iOS you have to double-tap, and select an app from the bottom dock to switch to. Android has the same problem- you press the home button, and choose an app to switch to. Both forces the user to focus on managing apps, instead of focusing on the desired "task".