As someone who has wasted many hours debating which JavaScript style guide to follow I disagree with this. Go have quite frankly put to bed any debates or arguments over "curly brace on same line or below" by setting a style and having it policed by the compiler. When working in a team it's good to have an official style guide that's enforced, in the long run this is a good thing.
I don't think this was done because Go's developers are opinionated, I think they looked at other languages and seen the mess that can happen when you don't set a style guide and thought "we're not doing that"