I'm certainly not qualified to answer. But there has certinally been some very impressive code written by people who spend a huge amount of their time in game development, kernel development, or any other large system that is written exclusively in C.

Frankly, even if Unix was that project, I'd expect that the "best" C programmer may actually be someone who is in a much visible position.

Then again, Ken may very well be the best C programmer, but Go doesn't much seem like a language designed to address the issues that C is currently being used to address. Frankly, it seems like a much better Java replacement IMO.