I guess I shouldn't be surprised. Ive's G4 Cube will always stand out to me as the worst computer I've ever used because the power button was hidden underneath it. It seems like form-over-function has always been his style.
I think the Cube was pretty well designed, it's fanless and practically silent (apart from the HD), and opening it up is amazingly easy: https://youtu.be/AwDOJ7HztXM?t=179
I wasted literally 30 min trying to figure out how to turn one of those on in a photo lab in college (before Google and wifi were in all pockets all the time).
Even the lab tech had no idea.
If I was going to point to what went wrong with Ive designs I'd point to laptop keyboards, and the flat graphic design of iOS 7, which ruined many of the affordances of the interface.
A more fitting term here, perhaps, is "affordance" (though "discoverable" is also accurate, but "affordance" is a more technical term here).
A mug without a handle can burn your hand. Adding the handle is a way to avoid that. The handle itself is usually designed to look like a handle. It's clear what the handle does, based solely on its form. You don't need a manual or an example or a hint to use the handle - most people, intuitively, will use the handle as intended.
The handle has "affordance". Waving your hand over the top of a computer in order to use a 'button', in contrast, has little to no affordance. The comma on this site acting as a button has no affordance. And so on.
You can wave your hand over anything (unless something is blocking your way or is too far, etc.), therefore most stuff affords being waved over.
A mug, with or without a handle, affords "being held with your hand"(although more or less comfortably).
What you're talking about is a signifier.
Quoting from a random article:
As Don Norman explains it: “[…] although affordances make sense for interaction with physical objects, they are confusing when dealing with virtual ones. As a result, affordances have created much confusion in the world of design. Affordances define what actions are possible. Signifiers specify how people discover those possibilities: signifiers are signs, perceptible signals of what can be done. Signifiers are of far more importance to designers than are affordances.” [Donald A. Norman, The Design of Everyday Things: Revised and Expanded Edition, 2013, pXIV-XV]