Their main problem isn't the fact that the use the same ole franchises... its that they don't release often enough in those.
There shouldn't be one game per franchise per platform...
But... they have more than "The Triad". To plagarize someone else:
> Nintendo has Zelda (action/adventure), Xeno series (JRPG), Fire Emblem (SRPG), Mario (Platformer, Kart Racer, RPG, Sports), Pikmin (RTS), StarFox (Dogfighter, on rails shooter), Splatoon (TPS), Kirby (Platformer/Action), Animal Crossing (Simulation), Pokemon (JRPG), Metroid (Platformer/Shooter, FPS), Smash Bros (Fighter).
If they could release those on a regular schedule AND stoke the fires for 3rd party? And damn if being based on Unity won't kick THAT fire... They will own the next few years.