The main reasons for Clojure to use the JVM was (IIRC) twofold: Access to a large ecosystem where basically every idea has a library available already and being

The main reasons for Clojure to use the JVM was (IIRC) twofold: Access to a large ecosystem where basically every idea has a library available already and being immediately productive because not needing to learn a new runtime (+ previous point of libraries already being available). With those two reasons in mind, at the time Clojure was created, it made a lot of sense to use the JVM.