We built a heavily asynchronous back-end communications service in Go a year or two ago. It was a great learning experience. I learned that I don't like Go and its limitations and design choices first hand, wrote a bunch of notes about what I did and didn't like (mostly didn't like), and moved on.
We had chosen Go to use for the reasons others here have commented about (especially the part about enabling relatively inexperienced software engineers to be productive quickly), but in the end I felt it sacrificed too much on that altar and I would rather spend more time mentoring and training our software engineers to use tools I felt were better.
It's mostly a matter of opinion, like I said - with sufficient dedication you can pretty much do anything with any language. But I'm not investing any more time into Go when I have other tools out there (like Clojure, Rust, Haskell, Common Lisp, C#, various BEAM languages, Ruby/Python, etc.) that I find to be uniformly more pleasant to use.