I think they should make more games aimed at older players first with themes that don't so far over the top that they're inaccessible to kids entirely. But the majority of the Nintendo fanbase moving forward is going to be adults, it's the same shifting in demographics that happened to the comic book industry over time.
If that means Hotel Dusk, fine, but why not an online shooter? Why not an open world Western style RPG? Why not a battle royale style game? If Xenoblade X can sell 1.5-2 mill on the Switch, given that its a Japanese RPG (not exactly the most mainstream genre), IMO a Nintendo shooter in the vein of Perfect Dark or GoldenEye (tone more for adults, but not exactly over the top violent) today would sell 3+ million copies, Nintendo making a game like Overwatch or Fortnite would clean up.