https://en.wikipedia.org/wiki/List_of_copyright_case_law
https://en.wikipedia.org/wiki/List_of_patent_case_law
https://en.wikipedia.org/wiki/List_of_trademark_case_law
https://en.wikipedia.org/wiki/List_of_United_States_patent_l...
https://en.wikipedia.org/wiki/List_of_United_States_Supreme_...
https://en.wikipedia.org/wiki/List_of_United_States_Supreme_...
https://en.wikipedia.org/wiki/List_of_United_States_Supreme_...
Did you not know this?
There are legal issues around how to legally obtain emulatable copies of the games you own, but emulation is absolutely legal.
(This is not a commentary on whether the emulators in question were careful in every other way.)
Still, Nintendo's motive is to defend their IP.
Even if the lawsuits go nowhere, it still works for them.
See, https://www.pcgamer.com/gaming-industry/switch-emulator-ryuj....
If Nintendo's IP wasn't involved they wouldn't give a rat ass about the emulation scene.