[jeremyjh]

Except they didn't. Go has generic maps and slices. It was never their goal to create a language without generics. What happened is they failed to come up with a satisfactory design for user defined generics in time to make Go version 1.

[zadokshi]

Exactly, They didn’t feel it was important. It was not part of the language design.

https://golang.org/doc/faq#generics