[StavrosK]

Isn't everyone "using" everything? Unless a large percentage of the code the company is currently using is in a language, I don't consider the company to be "using" the language.

[dcwca]

So nobody's really using anything unless they use it exclusively? I guess nobody's using anything then. Google isn't using Go. Microsoft isn't using C#.

[abritinthebay]

A significant amount of the code in many of those companies is Node - especially in non-legacy code.

Your comment ignores legacy code bases, which are common at large companies, in favor of an unrealistic yard stick.