Actually the MS 'Metro' design used in the ZuneHD and Windows Phone UI (best Home screen design by far) were both more logical and discoverable than the iOS UI (well until they released the Win Phone 10 UI with the hamburger menus...), but everyone just learned how to navigate iOS because 'everyone's doing it.'
I still believe the iOS UI is terrible. Navigation is all over the place, the wall of icons gives no preference to priority (other than creating folders), the icons and colours change (as mentioned in the article) and interaction is inconsistent (press/long-press).
But everyone learnt the interface so now it's 'good.'
I don't mind learning a new interface or even coming up to speed with an entirely new UI paradigm, if there's something in it for me. But my objection is that as soon as I learn it, someone who is paid to look busy will change it for no reason other than to justify their role in the company hierarchy.
Obvious examples include almost anything from Microsoft ("Metro^H^H^H^H^HWindows 10 is awesome! You just don't like change!") or Google ("We have altered GMail. Pray all you want, we're going to alter it further"), but Apple is far from guiltless.
When that happens, it's hard to escape the feeling that your time is being wasted... and as you suggest, the older you get the bigger a deal that is.