> I think the point isn't that is impossible to be able to do a clean install of an OS and apps (Time Machine included) you have already paid (premium!) for but the fact that it is non-trivial and very much involved - all the things for which the Apple system stood against.

I'm not sure I agree?

Apple's always optimized for the average person's average case. "Those of us that need to maintain machines" aren't the average person engaged in the average case activity; they're engaged in a corner case activity and should have the knowledge to swing the non-trivial (but still trivial) ISO extraction method.

This is a small inconvenience for a small section of their customer base with a big upside: updating one OS version to the next over the internet is dead-stupid easy for the non-technical majority.

It beats the hell out of what for years has passed as Microsoft's version of selling you an OS upgrade over the internet; paying for a download of an .iso, figuring out what to do with an .iso, burning it, and using it is easier for the "those of us that need to maintain machines", but way out of reach for the non-technical majority. It's optimizing for exactly the wrong case.