It's the ongoing problem of developer capacity at Nintendo, especially when you need the biggest studios focused on the games that are really going to move hardware. Franchises like F-Zero, Starfox, and Metroid get caught out in the cold with no-one out there dedicated to making them work.
As Viper said, the new R&D building will help with that, though we likely won't see the fruits of that labor until late in this generation.

Monster Hunter: pissing me off since 2010.







