It seems to me that achievements are popular mostly in the west, which is why Nintendo overlooked it.
Personally, I don't care too much... Most games I play, I never notice when I unlock achievements... I also think a lot of the achievements are ridiculously dumb (You threw a grenade! Wow!) ... so personally, I get no incentive to play games when achievements are involved.
But I can see why they should've been included to draw the 360/ps3 crowd in more. Ah... well.