My apologies for starting a PC vs. Mac rant: I mistakenly thought you were re-opening the rants about iDrive vis-a-vis it's OS being a version of Windows (I don't know if that's still true, as the original iDrive was.) As Dan succinctly states, it's _mostly_ opinion on what is better when it comes to UI design.
However, to address your statement, the new iDrive controller has more in common with a Microsoft Mouse (which has 4 buttons, it's primary cursor movement and a roller for scrolling) than the Mac mouse. (This use of a "wider" philosophy is well-accepted by UI research that shows "breadth" is better than "depth" when it comes to menu systems.) BMW's original iDrive didn't adhere to this design mandate, and look where that got them.
So, you could say that BMW has adapted Microsoft's mouse design ... ;->
FloydR