If you think how the whole web development has been changing from server-side generated views to more "produce data and send it over as JSON" style services, Node.js and others start to make a lot more sense. That said, the post has point that on more established platform you can expect to be more productive since you have more established work flows and standard libraries.

Btw. note the terminology: Node.js should not be called "framework", it's a platform. "Framework" is something that runs on platform and you extend/modify it's functionality by writing code. "Library" is something which you call/use from your code.