When it comes to Apple's design decisions, they absolutely have no idea what they are doing with all of these disgusting flourishes. see this article: http://www.fastcodesign.com/1670760/will-apples-tacky-softwa...
But I guess I'm giving Apple the benefit of the doubt: although I personally agree that some of their designs are tacky and over the top, I trust them enough to assume they have their reasons.
"Skeuomorphism is a catch-all term for when objects retain ornamental elements of past, derivative iterations--elements that are no longer necessary to the current objects’ functions."
Then Sacha Grief, might be wrong. The example he given, used blue leather and white buttons and he derided the example as not skeuomorphism. But in that example only a part of it was the ornament (i.e. blue leather). I could be wrong but what does ornamental take into account? Whole thing or just a part?
I mean rest of his story does make sense, but it's still an invalid example.
EDIT: It might be a nitpick, but I like to know what is and isn't skeuomorphic.
Glass thermometer iPhone app: skeuomorphic.
Wooden thermometer iPhone app: not skeuomorphic, because real thermometers do not use wood.
If I translate a physical object into a digital version and replicate ornaments that add no function in the digital version (ie. a leather texture), that's considered skeumorphic. On the other hand, if I apply a leather texture to my UI for random app X, that's not skeumorphic.