A modern programming language that makes developers happier.

kotlinlang

Another question. As I am a consultant, I work for different organisations over time and although I try to spread the enthusiasm of Kotlin I often get 'resistance' from Java developers. Most saying something like 'why bother, eventually this ... (feature of Kotlin) will arive at Java'. Almost all developers I meet which switched to Kotlin do not want to switch back (voluntarily) because the language just feels nicer and makes them happier and more productive.
I am wondering how others deal with this and what ideas people have in helping other developers switch over?