[pjmlp]

I know it is divisive, yet many Kotlin folks don't appreciate the platform that makes their ecosystem possible in first place.

From all the JVM guest languages, possibly fostered by Android team, they are the most anti-Java ecosystem.

Clojure folks appreciate being a hosted language, Scala is kind of they would rather have Haskell but still JVM is kind of cool, Groovy was usually a way to script applications.

Kotlin, well those behave as if ever the JVM would be one day rewriten in Kotlin, they have Android for that.

The features you mention will never be supported in Android by the way, at least I don't believe Google will ever bother to do so.

[rhdunn]

I view the relationship between Kotlin and Java like that between C++ and C.

The two-way interop is one of Kotlin's advantages as it makes porting code from Java to Kotlin easier, or using existing Java libraries. For example, you don't have/need something like Scala's `asJava` and `asScala` mappers as the language/standard library does that mapping for you.

The interop isn't always perfect or clean due to the differences in the languages. But that's similar to writing virtual function tables in C -- you can do it, and have interop between C and C++ (such as with COM) but you often end up exposing internal details.