As for a future with gamers who only watch their games, remember Nintendo patented it so non-Nintendo games won't have the feature anyway.
Yeah but patents are usually very specific. Nintendo can't just say "the game plays itself if you want" and earn a patent. So if it took off other developers could just do something similar but technically different. Case in point my suggestion of making the "instant win" an item of sorts with limited uses is technically different than Nintendo's feature. Somebody could do that and effectively offer the same thing.
Is Nintendo's idea just literally a video or does the game actually play itself? Whatever it is, do the opposite, and you would likely get around the patent and provide similar functionality to the player.