How was the NES, GB, or SNES any less "kiddie" than the Nintendos that came after it? They weren't.
A solid and fun game with a "kiddie" tone is greater than a crappy "mature" game, only dubbed so for weak superficial reasons (EXCESS and NEEDLESS sex, gore, and language).
I think a lot of the games that get a M rating from ESRB should get a "T". Like Half-Life 2 for example. That was a very sincere, intelligent game. It shouldn't be limited to "M" rating just because of some moderate realistic violence. A serious or complex story also shouldn't be limited to an "M" audience.
Stuff with a consistently profane, asinine tone to it, like Duke Nukem or Mortal Kombat, sure. That can be labeled as "Mature". But they should change it to "P", for "Profane". Since using "Mature" is pretty ironic.
ANYWAY, I won't even consider either console until at least the first revision (2000, Lite, whatever).