For a very loose definition of "need".
> Did you ever tried implementing a desktop UI using an object-oriented multi-platform toolkit like SWT or QT or GTK?
There's an abundance of desktop application code written in JS from the GTK+ folks themselves. They embraced SpiderMonkey (the Mozilla JS engine) years ago and have been shipping stuff on it for just as long. Anyone who has booted into the default desktop on Ubuntu—or any other installation running Gnome—has already come in contact with it, perhaps even today. That doesn't get a lot of attention, though, because it's not "squeaky": it isn't plagued by the same problems that people (stupidly) associate with "JavaScript" despite the fact that what they're really thinking of are problems with the NodeJS/NPM community in particular and its spectacular tooling + other webdev-oriented accomplishments. I.e., all the things it insists are requirements for the Modern Programmer—a mission which their detractors assist them on by perpetuating the story themselves (cf "need")...