There are lots of other shiny new things that he could have learned. Clojure happens to be a rather practical new language to learn if you already know Java, and ClojureScript has a pretty small hump if you already know Clojure and JavaScript (which, lest anyone forget, is about 15 years old now).
Yeah, I never said I don't want to learn new things. I still have a desire to be employable, and if something new seems novel I'll look into it. But I have, for example, no desire to learn any new OOP languages (aside from a quick look) until the ones I already know become irrelevant.
