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.
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#.
Clearly, Node is widely used. It would be silly to deny that. The real question is to what extent is it being used, i.e., is it used to write large, mission-critical systems, is it used beyond developing client-facing web applications (which tend not to be very big), is it used company-wide in lieu of previous language infrastructures such as Java, C#, Python and C++? Now, that would be impressive.