I have to say that I don't really recognise that thing about using JDK classes. I've worked with Clojure for 2 years on a big government project (maybe 50 Clojure devs) and it was full-stack Clojure all the way down. We never used any Java libraries either, but of course basic Java/JS interop is a pretty normal occurrence in Clojure when doing a certain type of code (like reading and writing certain binary files to disk, you'd probably reach for the Java Standard Library). For 99% you need no interop in Clojure. ClojureScript is a bit different as you often do need to access HTML elements or various singleton objects like js/window or js/document and have to use JS interop.
I have to concur with you mate, I've used Clojure now for 6 years in 2 startups and I can almost count on 2 hands the number of times I've had to interop directly with Java classes to get something to work.
