Well, it's not exactly the same. You can install another compiler on Unix, or compile it, and ignore C if you have time and talent.

On the browser we are stuck. It's sandboxed and restricted by the network so you can't install whatever you want. The user will install only what he wants, and he usually knows jack not does he want to wait more then 3 seconds.

So unless webassembly becomes the savior, JS is on terrible, horrible only path to the Web plateform.