Why do you think they have an issue?
Isn't it more logical to assume that their games just don't sell enough on Nintendo consoles to be worth the extra time, effort and money that's required to port them?
FIFA and Skyrim sold about the same. Doom sold less. Still, look at Bethesda and their ports to the Switch and compare to EA. EA has FIFA (and the Legacy edition at that) and more independent stuff they publish: Unravel and Fe. Nobody thinks they port Battlefield, Anthem or Star Wars, but what about the Sims, Need for Speed, Mass Effect, Dragon Age (Skyrim was also an older game), Madden, Boom Blox (why not), Spore or Plants vs. Zombies (again: why not).
I know, Switch fans love to pile hate on Capcom, but while some ports are crappy, Capcom ported over nearly their full catalogue. And they often sold a lot less than FIFA. Now you say: but FIFA sells more on other platforms. True, but who cares. Porting FIFA is not more expensive than porting Dragon's Dogma and it sold more, so it made money for EA. EA doesn't port stuff to Switch not because of sales, but because they don't want to. And they are big enough to get away with it. Capcom takes the money from cheap Switch-ports happily, to finance the next Resident Evil for PS5.