As others have said, it's not worth breaking away from the standard language only to make a few shallow changes. It needs to be a fairly radical improvement or

As others have said, it's not worth breaking away from the standard language only to make a few shallow changes. It needs to be a fairly radical improvement or it's just not worth it. If Kotlin were too similar to Java, it couldn't have offered much reason to adopt it. If you want a modern language that compiles down to C (not C++), there's Vala. It even has some kind of async support now.