The main focus of go is to be as simple as possible. It's not that they don't known how to write complicated programs under the hood and keep it simple outside

The main focus of go is to be as simple as possible. It's not that they don't known how to write complicated programs under the hood and keep it simple outside. They want to keep the programming language simple even under the hood where ever possible. Consider implementing a feature in hurry just because many people were asking, one needs to maintain them for the rest of their life even if they hate it so much, because of backward compatibility. It can also be the root cause for many problems. If generics make language complicated, then it's better they don't implement it in the first place.