> While Storm's Clojure implementation served it well for many years, it was often cited as a barrier for entry to new contributors. Storm's codebase is now more accessible to developers who don't want to learn Clojure in order to contribute.

It is interesting to contrast this with state of affairs in Apache Spark. Spark has thrived well in spite of being a Scala project; Scala arguably has a higher barrier for entry compared to Clojure (although the flavour of Scala used within Spark closely resembles Java).