The default template language is also really archaic and no one has created a solid alternative yet that's actually well tested and used by the masses.
It might have good execution speed and the language itself might be nice but the only thing that matters is going from point A to point B. Go will not get you there faster than other languages and the execution speed is a non-issue for pretty much every platform (even rails) if you use tools available to you to their fullest.
P.S., I compared Go to Node almost a year ago and even wrote a mini framework for Go to resemble a smaller version of Express. I eventually just said fk it and stopped because the gains were not even close to being worth it.