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.
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