Before Nintendo would ever put any content onto the App Store, it would first have to be ready to compete in that environment and sell its games on a platform where race-to-the-bottom pricing and aggressive freemium money-making mechanics are the norm.
Super Mario Bros. 3 is an amazing game, but would it be as much fun on a touch screen with virtual buttons? No, it would not. And before you argue, but you can hook up a Bluetooth gamepad to your phone, think about how that changes the situation. If Nintendo is designing mobile games for the tiny number of people who go to the trouble of using an external controller with their mobile device, it’s no longer going after the millions upon millions of casual consumers that presumably are the entire reason it would go mobile in the first place.
Moreover, if you like Nintendo’s games as they are, you should want Nintendo to run its own platform. I wonder if any of the Underpants Gnomes understand why, exactly, Nintendo’s games are so unique. Nintendo has the freedom to create games unlike anything else in the world precisely because it has always controlled the entire gameplay experience from hardware to software.
Chill out guys, Nintendo isn't going anywhere.