That likely explains the Steam Deck's popularity for modding old Nintendo games over Xbox and PlayStation titles. Such a shame ex-Nintendo fans are modding other systems to play Nintendo to somehow destroy and boycott Nintendo. Meh.
Well, no. Not, really. It's a combination of ease of use, availability and the age of the games.
Xbox/Xbox 360 emulation is still in its infancy. Plus, most of the best games Microsoft put out for Xbox & Xbox 360 have been available on their digital storefront for nearly 20 years at this point, plus in some cases you can take a 23 or 24 year old original Xbox disc, put it in your Series X and just play the game. So the availability of the old titles combined with the difficulty of emulation makes the Xbox & 360 less desirable to emulate.
On the other hand, Nintendo is just now making Gamecube titles available again after 20 years. Plus, or maybe because of that, Gamecube emulation just works much better than Xbox emulation. So the ease of use combined with the unavailability of titles for nearly two decades has made Gamecube emulation more popular than Xbox emulation.
When it comes to older generations, a lot of the popular Nintendo games are older than the popular Xbox/PS games. I think it's harder to sell people on paying for an NES game that's 40 years old, than it is to sell them on paying for a 15-year-old game. Like, if you want to sell me Skyrim, OK, sure, that's a 13-year-old game, but it's pretty robust and I can sink a lot of hours into it. Super Mario Bros 1? Not so much.
And to be frank here if you think someone who wants to play Super Mario Bros on their Steamdeck is doing some kind of significant financial harm to Nintendo and is making some sort of conscious boycott of Nintendo, I think you are 100% incorrect. They just don't feel bad about pirating a 40-year-old game that they've probably already paid Nintendo for multiple times between all the times its been released over the years and would rather download it for something they already have as opposed to shelling out the money for Switch online and a Switch to play 7-8 30-40 year old NES & SNES games. That guy was never going to buy a Switch to play these games.
I mean, honestly, between my original copy, an import copy I got for $5, the version I bought for Wii VC, and the version on my SNES classic, I already have four 100% legal copies of Super Mario World, maybe more that I'm forgetting to be frank. The market is so saturated with these old Nintendo games between the originals and rereleases, it wouldn't be much of a stretch to think anyone over the age of 30 who is a Nintendo fan already has a legal copy of a few old Nintendo games between VC for Wii, WiiU & 3DS, the classic systems, and old copies of games sitting in people's closets. Do you really expect them to pay for Switch online for the right to play these games at this point?
Finally, emulation for PS1, PSP and Sega's consoles is absolutely just as rampant as it is for Nintendo, but their back catalogue is not as popular. Trying to portray emulation as a Nintendo problem is extremely misleading. The reviews for the emulation devices have Genesis/PS1/PSP/Dreamcast games front and centre next to the Nintendo titles.
