Nintendo don't need to maintain their current output. No one is going to cry if Mario vs Donkey Kong or Nintendoland or Game & Wario don't exist anymore. When Nintendo goes third party they'll still make all the big games that sell. The ones that don't sell, well by definition they're not gonna be too missed.
using the sega analogy: this is why we basically have sonic titles now, with a few others here & there
thankfully you're not speaking for anyone but yourself here