simply human nature, dear Watson. we covet shiny rocks, and metals, and put price tags on animals. objects with no actual value outside of the human species, that merely exist, and nothing else. why would a system of operations be so different. well ... because its shiny, and therfore, valuable. cha-ching.
as for the DX 10 & 11 comparison. it looks pretty much the same. sometimes i dont see much difference between 9 and 10 versions of games. might just be me, or it may just be that particular game, but i dont see much improvement. time will tell, i suppose