I think comparing Go and Haskell are like comparing two incomparable different species -- a fish vs. a cat.

Why? Because Haskell is an interpreted language while Go is a compiled one. Interpreted language doesn't care much about performance as it isn't designed for that purpose, while in the other hand, compiled language does. As a result, interpreted language tends to be more 'elegant' and has lots of convenient features at the cost of performance. A concrete example is when you talk about preventing unacceptable data type in Haskell. They could make it so in Go, but the performance cost would be undesirable.

IIRC, I read that they designed Go to be practical instead of 'elegant', the reason is so that people can learn it easily, making it a good alternative for other compiled languages like C++ whose learning curve is hugeeee and ugly!