Not sure what you mean, there are a ton of Nintendo emulators out there, some decades old.

Just a bad joke.

It only became a problem when emulator performance overtook their current-gen hardware

(Especially if enhanced versions of big titles like the Zelda games are intended to be a significant selling point for their next console)

I mean, Higan/BSnes, SNES9X, Project64, Mupen64, FCEUX, mGBA, and probably dozens of others that I'm missing have been around for a very long time, and as far as I'm aware haven't had any legal issues from Nintendo, though that might be because all of them don't require any kind of BIOS.