Lots of places are Java™ shops, and adding new shiny stuff from the NodeJS ecosystem for frontend work can be difficult. I couple years ago I had to build a weird multi-step build bridge between babel and the Grails asset pipeline. A pure JVM implementation would probably make this sort of thing less painful for a lot of companies.
Ah ok, so this makes it easier to integrate react into the view layer for a traditional java mvc application is that right?
Yep, lowers the entry barrier to add it to a project. I think most of the modern frameworks have decent support out of the box but for projects started a decade ago it's useful
It's not only npm, its also jsx transpilation, bundling (incl. a shim of npm, es6 imports and html-imports) and java-javascript interfacing.