In the last Nintendo Direct, it was announced that Super Nintendo games were coming to the New Nintendo 3DS. This left a lot of people questioning why the games could not be released on the original 3DS hardware. An explanation on why this is the case was given from Nintendo to Game Informer. This is what they had to say.
“As previously announced, New Nintendo 3DS has an improved CPU, which enables Super NES games to run on the system with quality results,” Game Informer was told by a Nintendo representative. “The Super NES games also include Perfect-Pixel mode, which allows players to see their games in their original TV resolution and aspect resolution.”