Hopefully, we'll have Scala support with Java 9, when Quasar is expected to work will all JVM languages automatically. We might also add support beforehand, but the problem is that supporting Scala is a large effort, due to its complicated compilation, which isn't justified by the number of Scala developers, compounded by the fact that developers who like monads -- and developers who choose Scala often like monads -- will find the excellent Akka framework very satisfactory. Clojure and Kotlin have far fewer users, but supporting them is easy, as their compilation is fairly straightforward.
We are, however, more than happy to accept contributions towards supporting Scala.
Well as you can see HN is heavily biased towards Scala (they are downvoting you for no reason, while a very unprofessional comment above gets upvoted). Anyways, thank you for being awesome and working on Quasar and the other PU project opensourced.
I suspect that they are downvoting the poster rather than the comment, due to previous posts. I upvoted pron's comment since it was a professional response to the question asked.
I am not sure if butt-hurt is the technical terminology I would use here. They don't want to be put up with Scala, please respect their decision as much as everybody else respect yours.
We are, however, more than happy to accept contributions towards supporting Scala.