Nintendo is happy Sony/Microsoft don't cater to the younger generation, as it lets Nintendo foster lifelong fans

Sony and Microsoft may have some games on their platforms that are friendly to all ages, but they're output is nothing like Nintendo. The Big N creates franchises that can be enjoyed by all ages, and is usually more than appropriate for even the youngest of kids. According to Nintendo's Reggie Fils-Aime, they're happy that Sony/Microsoft don't pay much attention to the younger crowd.

“We are happy that they don’t. It’s been an incredibly important market because the kid who’s 5 or 6 today is going to be 12 or 13 and not all that many years later 18 or 19 … And when you have an affinity for Pokémon or The Legend of Zelda series or Mario Kart or Super Mario Bros. that affinity carries with you.”