Just to provide a contrasting point of view: CoffeeScript is the only reason I ever wrote, and ever write, JavaScript. Period. Transpilers do add a layer of complexity, but all of the syntax sugar advantages make it more than worth it to me.

I would not ever write JavaScript if CoffeeScript or similar languages did not exist. Before it existed, I never touched the language. I now use CoffeeScript daily and have never been happier. A watchdog script automatically transpiles the code upon updates, and everything is completely seamless for me.