Earlier quoted context omitted.
The JVM is a great platform if the language in question is relatively close to Java, and you're just layering on higher-level syntax like closures. (Sure, it would be nice if Java supported them, but they're not hard to implement as anonymous inner classes, and to simulate real closing over variables you just need to wrap all captured variables in one-element arrays or other wrapper objects at the declaration side. I…
Maybe it is because the strategy more closely resembles the relationship between the CLR and DLR than the JVM and nothing. Like you said the JVM is not dynamic language friendly, and Sun/Oracle has really shown much interest in making it so.
Isn't the DaVinci/MLVM project an example of how Sun actually tried to move towards dynamic and non-java languages in the JVM? invokedynamic & method handles are already in the upcoming java 7, and that goes a long way towards supporting dynamic languages on the JVM.