Even browsers recognize how problematic JS is. We have a "use strict" mode that take the edge of the worst ambiguities. We even have a "use asm" to support compiled runtimes like Emscripten with an optimizable subset of JS. And the likes of Firefox / Chrome will look for a .map file when you debug JS and will show you the input source - unminified js / cs / ts / dart / whatever if it finds one. Basically they know JS sucks and are trying to facilitate devs who use another language.