It seems to mostly boil down to the fact that they were able to work together with the Dart team to integrate the tooling, compiler and VM to provide a good deb

It seems to mostly boil down to the fact that they were able to work together with the Dart team to integrate the tooling, compiler and VM to provide a good debugging and hot reloading experience. Kotlin/Native was not really ready at the time they started on Flutter. But otherwise, I think Kotlin would be a much better fit, since it has fairly unique features to support building UI hierarchies[1] in code the way Flutter wants to do[2], which Dart lacks. They way this kind of code has to be written in Dart reminds me of old Java code, with callbacks using anonymous classes for lack of lambda functions. [1] https://kotlinlang.org/docs/reference/type-safe-builders.html https://kotlinlang.org/docs/reference/type-safe-builders.htm... [2] https://flutter.io/docs/development/ui/layout#step-2-implement-the-title-row https://flutter.io/docs/development/ui/layout#step-2-impleme...