Lots of dyed leathers have a tendency to take scratches, scuffs, etc., and generally weather over time. A lot of folks love this effect, especially on furniture, shoes, jackets, and other items made of leather. Other folks either don't care for the effect, or simply haven't owned leather items long enough for the distressing to kick in. My guess is that Apple is preparing that latter set of consumers for some sort of weathering/distressing over time.