I imagine that they would have, but for the following:
I'm sure that clojure compiles clojure, at this point, at least for the majority.
So, once you've written something that compiles clojure to js, then you just need to compile that compiler to js.
Why haven't they done this? My guess is that "something" in the clojure compiler relies on the jvm, or links to some java code to do its work.
Another possible reason that clojurescript doesn't yet compile all valid clojure.
In any case, I'm sure that this is an eventual goal. Hickey has stated that he always wanted clojure to target multiple platforms, but decided to start on java first.
