Why has Nintendo not put in a achievement system in the 3DS/Wii and has the HD twins missed a golden opportunity?

[spaceguy]

SWORDF1SH said:
because grans and 5 year olds dont care for acheivements

What about us old school gamers that want to get rewarded for the old games on nintendo. I would have bought a lot more games had they made it a challenge and thats what achievements add.