Putting a second analog stick on the 3DS XL would have meant a compromise elsewhere, according to Nintendo Japan's president Satoru Iwata.
"When we looked at the design of the 3DS XL we had to look at various factors," Iwata said. "One was battery life, one was the overall size of the unit, and we had to make some trade-offs.
"The choice, if we were going to include a second analog stick was to reduce the size of the battery or make the unit much bigger."
Because Nintendo wanted a much bigger screen in comparison to the overall size of the system, the second analog stick was sacrificed, said Iwata.