dumb analogy, the issue is libraries, you don't need to read bytecode to be able to use a Java library in Java or Clojure but you do need to read Java. Same with Cljs and JS.
I have to say, one has to be some special kind of "dumb" to learn Clojure, but at the same time lose the ability to understand Javascript or Java. One doesn't choose one tool simply because "they don't know the other tool". Sometimes, and quite often, the decision gets made precisely because they gained significant knowledge in both.
