“It Just Works” Should Be the Next Step
In the end, I think that what the next ‘MacOS’ needs most is focus. Focus on what it has historically done best — ‘just working’. I don’t think that the current problems of OS X have much to do with its old age or its old models. It’s more a matter of identity. I feel that recent versions of OS X have tried to ‘look friendly’, as if to say Hey folks, I can be simple like iOS! Look, I too can have big app icons taking up the whole screen! I too can go full-screen with apps, and I can do split-view just as well! And I have Notification Centre like on iOS! and so on. This path of convergence with iOS hasn’t been all bad, but the process has involved an accumulation of new features which not always have brought more value or functionality, and often have introduced bugs or annoyances; all this has ultimately undermined the most important aspect of using a Mac — the ‘it just works’ aspect.
"I feel that recent versions of OS X have tried to ‘look friendly’, as if to say Hey folks, I can be simple like iOS!"
All traces to the Steve-o "Back To The Mac" keynote which made this an explicit goal.
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Also, while "It Just Works" would be an incredibly admirable target, considering just how aburdly far OS X has strayed from that in the last 6 years, it's a bit too unambitious.
"It Just Works" was always a bit of a simplification / dumbing down from what the Mac always really stood for, especially in the pre-Lion OS X variants. Namely: "Simple things should be simple, complex things should be possible."
"It Just Works" is a subset of that philosophy. It's a necessary subset, but OS X should be the whole thing.
Don't think Cupertino has interest in any of this, but if we're making wish lists...