He means that Go will not impress programming language geeks and academic PL researchers with cool evolved syntax or cutting edge features, but is a fine language for actually building software.
In the same sense that a language that "in theory" has tons of cool stuff might be unusuable in practice (due to complexity, opaqueness, lack of libs, strange syntax etc).
In the same sense that a language that "in theory" has tons of cool stuff might be unusuable in practice (due to complexity, opaqueness, lack of libs, strange syntax etc).