How come is that a bad thing. Like seriously. It takes fraction of time and money to port the game and if it's a good game, it will sell, easy money. Not to mention it's a bliss for the people who never owned the original system AND every game ported, particularly, to the Switch will get one of the best updates ever ... the portable mode.
By far the most common complaint I hear is "but I already own this game" ... so what? Just don't buy it. No one forces you to do so. If Nintendo releases some port, which somehow will require the other copy of the game *cough* MW remastered *cough*, then we'll talk.