Instance derivation is likely not impossible when typeclasses support is there. I wonder how expensive it could be, though. Making them also usable from Java (e.g. Comparable) would likely be problematic sometimes due to Java's inconsistencies.

Can receiver lambdas (the "DSL" feature) be used to produce something comparable? For something comparable to LINQ, though (same expression targeting e.g. an object graph and an SQL database), compiler support would likely be needed.

Also, you miss the point of Kotlin; it would be like saying that what you miss from Clojure is similarity to Java syntax.