The modern programming languages like Kotlin, Swift, Dart, Rust are good but the problem is they all are converging to the same language. For example, Java just got the closures; ES6 is getting classes; Swift has just taken differ from Go; Rust got algebric types; Kotlin is going to have asyc and await and Dart borrows them from c#. There is nothing 'new' or 'innovating' in anyone. If you see some other languages like Scala or Go — they are very different to program with yet they have perfect combination of own shaped concepts and have clear vision for innovating. That’s what I found disappointing with not only Kotlin but all these morden programming languages. YMMV.