Because its a console which also is a mobile device. It not only comes with one controller, but, depending on the game, the JoyCons allow two players to share them. Without buying additional hardware. They also happen to be complete Wiimotes with motion tracking - something you had to buy extra before. And of course, it is the best and most powerful gaming hardware made by Nintendo. A PS4 is cheaper and has more GPU power, if you don't mind it being a big box. And it doesn't play the Nintendo games.