This is understood. The point I'm making is that I believe flat is not inherently better or even good. Its a fad right now that apple is using for a good half step to a realtime 3D UI.
Sku was teaching designers to fake dimension by hand, flat will aid them to getting to the point of texturing real 3D objects. And if you think iOS7 doesn't still use 3D space to make skumorphic metaphors you haven't looked at Safari' tabs yet.
In this context, what do you mean by 'realtime' 3D? You can already use 3D transforms to your heart's content without any stutter, since at least the iPod 3G / iOS5.
Sku was teaching designers to fake dimension by hand, flat will aid them to getting to the point of texturing real 3D objects. And if you think iOS7 doesn't still use 3D space to make skumorphic metaphors you haven't looked at Safari' tabs yet.