Binaries are easily pirated, and can be de-compiled. Obfuscating a Javascript file is almost as effective for protecting your code.

Either way, the only way to protect your code 100% is to run it on your own machine, and not on the user's.

Because decompiling isn't a thing?

Because decompiling is a lot easier when your "executable" is a high level language built on top of a well known and heavily targeted VM.