I think Onyx and Cortex always were redundant. You have Kafka and Spark/SparkML and Storm, you can use them from Clojure without problems.

If Onyx had been the first, it could have become what Spark is, possibly.

My point being, I don't really think every language needs a distributed compute, just need one and have bindings from your language to use it. Clojure being Java has access to many bindings for many of those popular libraries.