Well, the fact is that other languages do not run on it at the full speed they could with their own custom VM. It's been many years of effort and dynamic langua

Well, the fact is that other languages do not run on it at the full speed they could with their own custom VM. It's been many years of effort and dynamic languages on the JVM still do not compete with native dynamic language VMs. But yes, for languages like Scala etc., they run quite well on the JVM, well enough for sure.