well, its unfortunate that React Native didn't work for them. i think RN is great solution and direction for mobile in general. sure it can be improved but at the moment, it is the best we have for cross-platform mobile development.
Is there actually something wrong with the language? If it's a matter of the issue of having to learn a new language, it's not as if there were many Objective-C, Swift, or Kotlin developers before mobile.