>MongoDB? PostgreSQL? Why don't we mention Python too since not every Javascript programmer is using NodeJS, oh wait - maybe we should start mentioning Haskell to JS compilers too, yes, because those are Javascript tools and libraries.

I don't understand this slippery slope argument. One can mention tools relevant to JS developent that are not themselves written in JS, without going to the extreme of listing everything under the sun.

Even if it's a little fuzzy when you stop, MongoDB is known to be a great tool for NodeJS projects, whereas everybody understands that the linker and the compiler is not really relevant to the discussion.