So many different reasons:
- Nintendo create games by concentrating and nailing the gameplay and game mechanics first to ensure they're easily accessible to a large audience. Everything else is secondary.
- Reusing well-known and popular characters for the past 20 yrs. Everyone knows Mario and Yoshi etc. so why not use them to sell a game in another genre?
- Linked to the last point, superb advertising and marketing.
- Not over-saturating your franchises with too many titles in too short space of time. Unlike Call of Duty and other franchises, you don't get that many Mario, Zelda, Kart, Smash Bros. games in a gen and Nintendo let the games sell for as long as possible.
- Linked to the first point: the games are targeted at the largest demographic possible meaning a much larger customer base.








