I think the issue is more complicated than that, and than many who want to see more third party support are willing to acknowledge. It's also more complicated than I'm about to write about, but I'm going to try and put the thoughts flying around my head into words:
Last edited by Machina - on 31 January 2020
Nintendo's audience has always been quite unique, whereas the other manufacturers have pretty much identical audiences, in terms of audience taste at any rate. I know there's some difference - we saw for example splits for a lot of third party games favoured PS4 over XO even more than the install market shares should have resulted in, but for the mostpart they're very, very similar.
There's certainly room for third parties on Nintendo consoles, and they can succeed, but often not if they're just regurgitating whatever it is they're releasing on Microsoft and Sony's platforms, especially where said regurgitation requires additional work to make it on par with the PS4/XO versions, soon to be PS5/XSX.
They need to put in effort, which in a way is a credit to Nintendo's fan base, in that it won't just buy 'Game X, 2020 Edition, Inferior Version'. And even when effort is put in there's very much a feeling that it's as likely to falter as it is to sell massive amounts. When 'Game X, 2020 Edition' can sell 10 million+ across Xbox, PlayStation, and PC I can understand why they're not so willing to risk putting in work to make 'New IP for Nintendo Fans', or even 'Game X, 2020 Edition, Main Version', when it's as likely to sell <1 million as it is 5 million+.
So, they often make excuses - EA being a prime example of a company that does this. 'Game X, 2020 Edition, Inferior Version' sold worse than any individual 'Main Version', and 'New IP for Nintendo Fans' did lukewarm to the point of irrelevance, so... why bother? It's too difficult and not worth the effort really, other than from a PR perspective.
None of these third party developers can create and cultivate an IP that would appeal to the main driver in the Nintendo audience that propels the likes of Mario Kart and Zelda to 5 million+ even on the worst performing Nintendo consoles. And if they could it probably wouldn't perform well on the PS5/XSX, so they're limiting their potential audience to a segment of one console's install base that's always been the hardest for them to capture, which makes it too risky to try.
And if Nintendo fans really want to play EA's output they'll just buy an 'Xbox Dumb Name That Seems Designed to Confuse Everyone', a PC, or a 'PS4,5,6,7,8,9' anyway, so.... *shrug*