If this was the case they would have gone 3rd party in the n64 or GC era when HW sales were too low compared to it's competitors now in the 7th gen, with their home console surpassing 86M and heading towards 90M and their competitors below 60M at this time I think they've done themselfs proud.
Buying in 2015: Captain toad: treasure tracker,
mario maker
new 3ds
yoshi woolly world
zelda U
majora's mask 3d