The creator of Mario himself Miyamoto gave a detailed response to Verge when questioned why Mario is coming to Smart Phones with Super Mario Run later this year on iPhone & iPad.
Miyamoto cited the success of Pokémon Go as validation of this smartphone-centric approach. “Pokémon Go is obviously a game that uses your GPS and it’s synced into the camera and Google Maps, so it’s a piece of software that’s really geared towards that mobile play experience,” Miyamoto said. “So, similarly with Mario, what we’re looking at is simple game play, one-handed gameplay; shorter play time, playing in shorter bursts; and then really bringing the joy of Mario to that much larger audience.”
That “much larger audience” is something that Miyamoto mentioned more than once — specifically in regards to upcoming generations of gamers. If Mario is going to live forever (or at least longer than the rest of us), he’s going to have to be a part of the lives of people born well after the 1980s. Miyamoto noted that there was a point in time when “[Nintendo’s] hardware system was really the first device that kids would interact with, and that’s starting to shift.” The first device kids interact with now, he says? Their parent’s smartphone. This notion of the smartphone “being the first place this kids are encountering games, is what helped us to decide to bring this to smartphones,” Miyamoto said.
He is more or less saying that due to kids first gaming devices being smart phones now instead of a Nintendo console, bringing Mario to mobile is critical in expanding the brand & series exposure for the newer generations. Miymato gives further comments in the below source link but this quote is really interesting and shows hows dedicated Nintendo is regarding making strong mobile products.