But here's the way I see it:
The (arguably) "natural" analogy is inherently different for a tablet versus a computer.
1. In a tablet you're actually touching the content - so the "natural" approach is for a finger movement to move the content. Hence the invention of "swiping", which feels completley natural from the first time you use it.
2. In a computer the thing you're touching is NOT the content but is analogous to a viewing device (such as a camera viewfinder) - so the "natural" result of moving that device is opposite to #1. And the scrollbar concept follows that analogy so provides consistency. Both the scrollbar and the two-finger swipe (original edition) have always felt completely natural from the first time you use them.
The conclusion I reach is that it was already "natural" and Apple shouldn't have messed with it. Not only was it already completley logical the "old" way but it also "felt" compeltley right and natural.
I realize its a metter of opinion but I do subscribe to the view that the "old" way works just fine, feels very natural, and is consistent across all platforms. Apple has really messed up the landscape by introducing a conflicting paradigm which will forever creat confusion and inconsistency.
PS - I suppose that the subtext is that Apple is preparing for a long-term trend, which is the merging of the tablet and computer paradigms (such as, perhaps, laptops with touch screens), in which case the question of "naturalness" becomes more murky...