Scala still has a better design at its base, which is missing from Java and I don’t see how Java can retro-fit it into the language, Immutability is a big part of being functional and doing safe multi-threading stuff, java is doing all the good syntactic stuff (case class, switches with guards etc) but without immutability it’s a far cry from the same facility in Scala land. Having said that, this trend is welcome for every time I have to write Java and makes it feel more natural to me as an old time Scala developer.