I had a conversation with Mr Journe this afternoon and asked him about it. The reason he gave, was that the rubber was needed on the original aluminium case to protect this rather soft metal from dings. Later this piece, became transformed to a titanium case and the gold case and platinum, and the rubber part remained. In hindsight it was no longer needed, since these metals are not as soft as Au, and he has chosen to take the rubber parts out - across the entire line.