Node is fast supposedly because it uses low-overhead single-threaded asynchronous calls, instead of threading. So if that is such a fast paradigm, why don't we build a low-overhead single-threaded asynchronous Java or Python or C# engine? Eg: Node.java, Node.cs, and Node.py?
There is no reason not to build a single-threaded, asynchronous web server in the language of your choice. I'd be surprised if there aren't a bunch of them out there by now.
Node has the advantage of using the same language for both client and server side code. Since JavaScript is the de facto standard for in-browser code, any other language pretty much requires a translation step.
Node also has a robust community and a lot of framework and library packages.
Java is actually mostly back-end these days, while JavaScript is decidedly browser-only, so the whole comparison is nonsense.
Have you not heard of Node.js? It is server-side JavaScript, built around Google's V8 execution engine.
To do nothing is to be nothing.