One of the major reasons why we went with Clojure for a commercial project was the maturity of the JVM platform, particularly the HotSpot VM. We really care about multiprocessing, pauseless GC (ConcMarkSweep does a good job here), low memory situations, JIT optimizing our code and overall stability. HotSpot has been great so far.

I do not want to spend time on debugging VM or dealing with its issues. I've had that with Common Lisp and I don't want to go back there.