Because Go is a badly designed language that only took off thanks to Docker, and as the article points out, a few C workarounds were anyway required to make it possible in first place.

I would have chosen C++, but given that isn't the new darling any longer as in the 1990's, that begs the question of the new kid in town that everyone is now rewriting everything into.

In 2013 C++ was having a moment. The C++11 standard was a huge release with meaningful improvements. It was a great time to start a new project with C++.