The reason why DS flashcarts have been so easy to get working on the 3ds is because of how completely broken the DS protection is. There is very little nintendo can do because if Nintendo's protection is too stringent, it will break playback for LEGIT users which would be a huge PR nightmare. Really, all nintendo can do right now is use a combination of white and black lists (white lists are a list of games that are acceptable, black lists are a list of games that are unacceptable) and indeed that's all the protections currently are for both 3DS and DSi to prevent DS flash carts.
3DS games, however, have an updated and more sophisticated copy protection system. There won't be any 3DS flash carts till the game encryption has been cracked... which means exploiting some sort of flaw in the 3DS firmware.
3DS games, however, have an updated and more sophisticated copy protection system. There won't be any 3DS flash carts till the game encryption has been cracked... which means exploiting some sort of flaw in the 3DS firmware.