Project lead here. I switched from C# to go for multiple reasons. One was that we were having strange platform-specific issues between different operating systems with the runtime. Another reason was due to some design issues causing the code to be very difficult to work in.
I was originally going to re-write it in C, but when I saw go, I immediately fell in love with it. In my mind it sits somewhere between C and C++. Yes it has a GC, but it's not obtrusive. Plus the language is simple and nice to work with.
Regardless of what language I use, someone's going to say it's a "bad" choice and others will say it's a "good" choice. Personally I believe the language is just a tool, and go is working out extremely well for us so far.