I disagree with the author about how it suffers from being on the JVM. In fact, I'm not quite sure the author even knows what the full scope of that sentiment means. I believe it is quite the contrary. With respect to the JVM not getting any better, it just did. "invokedynamic" was introduced with the latest release of JDK7 and is directly related to the support of dynamic language such as Clojure and JRuby. Using the JVM opens a bunch of doors for a burgeoning language that normally it would have to re-invent. In this case, because it is on the JVM it doesn't have to re-invent the wheel it can re-use existing and proven libraries, performance and monitoring tools, etc.
I will conceded that documentation can be spotty, but it isn't any worse than most new languages, and it is continually getting better. Furthermore, if you really want to give issue such strong opinions about a language you ought to spend mor time with it than just a day or 2.
IMHO your writeup is shallow and not well conceived.