I tried Clojure but ended up hating it for reasons all stemming from its hosted implementation. Whenever I didn't know how to do something, I (and most other Clojure users) would go use some JDK class (or worse, an external Java library) instead of figuring out how to write the Lisp.
For some reason this doesn't often happen with regular Lisp even though CFFI is available. There's a tendency to just reimplement it directly in Lisp, which is the more maintainable option.
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.
Hum, that's one of my favorite things. Some JDK APIs/libs are quite well designed, and when they are, Clojure doesn't bother re-inventing the wheel, which is a great thing in my opinion.
While I am an experienced Java developer, and took immediately to clojure, I don't think you deserved to be downvoted for expressing that experience.
I can imagine if I were to learn a new lisp, that was hosted on a language I did not know, and various difficult things leaked through the abstraction making it more difficult for me to work. I might feel similarly.
For some reason this doesn't often happen with regular Lisp even though CFFI is available. There's a tendency to just reimplement it directly in Lisp, which is the more maintainable option.