This is like the tail wagging a dog.
So Sega wants Nintendo to step it up to attract "hardcore" gamers to their games? Spend their money and valuable time?? OK, what about we put Zelda on hold to make a "mature" title so Sega can in turn make more sales for their games.
Halo 3 sales(highest selling game on 360): 8.1M
Gran Turismo 5 sales(highest selling game on PS3): 4.1M
When Wii Fit which is a $100 title outsells both Halo3 and GT5 Nintendo is obviously doing something right.
Now if Nintendo hires a third party to make a game for them then that's cool. But it certainly isn't up to Sega and it ESPECIALLY isn't a strategy to help 3rd party "Mature titles".
EDIT: I'm stopping here because I'm afraid we're getting closer and closer to a Hardcore Vs. Casual debate. Stopping myself first.