[JaimeThompson]

Because they wanted it to be actually usable by the vast majority of programmers developing real world solutions? Not saying that functional programming doesn't have a place but if it was as wonder as some people say it is it would take over the world because the shops that used it would way outperform those who don't but for most things that doesn't appear to happen.

[beatgammit]

That's a pretty poor argument. Functional programming isn't as popular because it's more difficult to learn, not because it's not as good. Sometimes the easier, almost as good solution is better than the technically superior option, especially if you need a ton of people to learn.

Functional programming is certainly better in a lot of ways, but Google wasn't trying to build a "good" language, they were trying to build a "good enough" language, which is why it doesn't really innovate, but merely pulls in familiar features into a simple package. Go isn't the best at anything, it's just good enough at several things, and very simple to learn, and that's exactly why Google uses it.

[AnimalMuppet]

No, they were trying to build a good language for their set of problems. Their set of problems include huge numbers of engineers, and code bases in the tens of millions of lines. They wanted short compile times, and ease of reading code. They weren't going to get either of those by something in the direction of Haskell.

And the result is not "just good enough". It's actually quite good for their problem set.