Well you don't have to be 'nostalgic' to like those games as Nintendo have made sure to release new iterations for every new hardware platform and also in different genre's than the original (Super Mario/Mario Kart).

Granted they are exclusive to Nintendo hardware which given their current diminishing hardware market share will mean less exposure, but it's not as if kids today don't know who Mario/Link/Samus are, only difference is that they know Mario/Link/Samus from the Wii/DS/3DS games instead of NES/SNES/N64 games.