I think you have to take the texture map driven interfaces as part of a larger package that includes the outside industrial design of Apple products. The outside package tends to be very futuristic and bare of details, so having the UI feature texturemaps of organic objects like wood or leather makes for a nice humanizing contrast. If you copy this on another device it's not quite the same thing, although if you look at the new Windows OS they did a great job of making something that looked very different.