It's important to remember that the JVM alone is a huge community. The fact that a lot of Ruby people don't understand the value of the JVM is really their own problem. The JVM is a far better runtime than any of the Ruby VMs, and it has a much better story when it comes to dependency management and packaging.

I don't actually see much value in having Clojure on LLVM as you'd have to build a whole ecosystem from scratch instead of being able to rely on the mature existing ecosystem that the JVM provides.