I'm pretty sure, if someone goes on stage at any Clojure conference and asks: "how many of you had to use JVM performance and monitoring tools" there won't be too many hands. And if you ask "how many of you have to read or write Java code every day to maintain your Clojure stack" there won't be too many hands either. You don't need to be an expert in JVM to successfully build, deploy and maintain stuff written in Clojure. It helps, but that's hardly a requirement. None of the most popular Clojure books really dive into JVM - it is not needed.