I don't understand why this is such a big draw for people when literally any jvm language has this feature. Languages like jython, ABCL, clojure, jruby, groovy, and perl6. Kotlin is certainly not unique in this regard.
Some of the languages you mention come with serious compromises when used on the JVM, like Jython and Jruby - decent portions of their ecosystems are implemented in C - and hence won't work on the JVM.
It's notable that projects like spark could have used Jython for its JVM/python interop, but chose py4j instead, consigning pyspark to some rather abysmal performance penalties under many conditions.
I'm not sure either. Your comment seems perfectly legitemate to me...