Any programmer who codes needs to type. Just like any programmer who creates a game needs to design it. When I say the programmer needs to implement something I don't mention obvious processes like "game design" just like I don't mention typing. I also think a dedicated role of a game designer is not required in many games, especially indie ones.

Additionally, emergent gameplay, by it's nature of being emergent is not really designed. It's a sort of iterative process of implementing a feature and testing the consequences.