> It helps tell these apps apart

I would agree, variation is very important in this respect - however, this skeuo-leather-morphic design is but one small niche in the set of all possible variations. Have Apple exhausted their own potential? Is the only way for them to further refine their software really for them to turn away from minimalism and add more and more revolting kitsch?

If this is true, why does it have to be this particular style of kitsch?