They don't lose money, they just don't get money they never could have gotten in the first place. Which makes it even more ridiculous.

Imagine someone "steals" your car tonight. Now imagine that when you get up in the morning, that car is still in your driveway in the exact condition you left it in. You haven't lost anything despite someone now rolling around town with an exact copy of your car.

As Gabe Newell famously stated "Piracy is almost always a service problem and not a pricing problem." Once the technical issues are solved, the fan-made emulators have always been superior to Nintendo's options. With better controller options, video filtering/scaling, and having access to the entire catalog. Meanwhile Nintendo offers a limited group that die with the console you bought it on on an objectively inferior emulator.