I think its a combination of their hardware design choices (simple buttons - A, B, X, Y, L R) and the simplicity of their games.
Alot of Nintendo games have a very clear premise which is immediately obvious when you start playing the games.
I think its mainly the control scheme though. People will much easier understand "press a to jump" than "press triangle" and in the latter you will just get a response of "WHICH ONE IS TRIANGLE!"








