I did a JVM targeting language as a research project, and was involved into porting KVM to an obscure architecture. It's been a while of course (early 00s) so maybe I misremember something or there were huge strides of progress in JVM.

Can you jump over 64Kb in bytecode yet? Allocate a lexically scoped variable?

Of course, enormous amount of work has been put into making this particular pig fly at reasonable speed. Doesn't change the fact that most usability complaints about Clojure stem from reliance on JVM piggybacking.