DKCR isn't a sprite based game though. 3D capabilities and 2D capabilities are separate things. Why would the 3DS get an inferior port when the Vita got a much better port? The 3DS port even had to be delayed to improve it (pushing up the dev costs). That suggests that they really struggled to convert the game onto the 3DS as the hardware wasn't as suitable, so when it then came out and sold far worse, that to me explains why Rayman Legends didn't see a 3DS release.