Nintendo tried to make money off of mobile the more honest way with Mario Run, but no one wanted it. On mobile the sad truth is, that people will buy more into these lootbox/subscription/in-game currency kind of things. Nintendo wants to make money and they simply do what works best for them (and many others). They tested the water with some mobile games and after that worked great for them they are now going all in it seems. As everyone always says, vote with your wallet: if you don't want that kind of stuff don't encourage it.
I don't like how these mobile games make their money and I don't play them. To me they are lackluster and small timekillers for a busride etc. Only very few actually stand out. I also doubt Nintendo will do this kind of stuff in their main releases, because they aren't stupid and everythings works perfectly fine for them this generation. People still want great singleplayer games despite what other game companies say, so Nintendo delivers them.