I think frontend developers are not pushing Javascript. They are pushing cross platform development and distribution environment with UI rendering, REPL, debugger and profiler, which is able to run on almost every consumer device. There are no competitors here. Unfortunately JS comes as the default language in that otherwise brilliant package. But it does not mean you should use JS - fortunately due to it's simple and permissive nature JS has become a platform for tens if not hundreds of other decent languages.