The problem with comparing smartphones with 3DS is the same as comparing an apple to a banana.
One is a phone. It is needed by most people in the world. It is used to make calls, send messages, browse the internet and many other things. One of them being gaming. But it's not a dedicated handheld gaming device. You don't buy a smartphone to play the games it comes with. you buy it to use it as a phone and maybe play a game or two.
The 3DS is a gaming device. It's made to play games, you can also browse the internet and do other things but it's not it's main function. You buy it to play games.
So in the end you can't really compare them! You can't compare the sales of a phone with the sales of a gaming machine! The phone is obviously going to win as it is more vital in everyone's life while the gaming device is just part of a hobby.
That is why it is unnecesary to make a smartphone that has buttons. People who game on it don't give a damn about having buttons as they don't really game that much to begin with. They will buy it... because it's also a phone. Just by adding buttons to it, doesn't mean you are making it a handheld gaming device... It's still a phone.
"I've Underestimated the Horse Power from Mario Kart 8, I'll Never Doubt the WiiU's Engine Again"
