Taking a task that a JavaScript developer could do and putting a dependency on them being a Scala developer as well isn't a win imo (as a Scala/Javascript dev)
I fully agree. I've done minor things in Java and I've been doing PHP for about 3 years. I've picked up React and I've been trying to get into Scala. It's only been three days, but I think it's not for the faint of heart. I can think of a number of solid front-end devs whose lives would be hell if you threw them into Scala (as an aside, I actually like what I've learned so far, though I wish their 'documentation' was not terrible, though I imagine it's probably done that way since it would be too hard to keep it up to date)