A Clojure programs takes 3-4 seconds to load, making it untenable for command-line programs.

Just compile it to native code with a native Java compiler, or NGEN/Mono AOT on the CLR side.

At least in the past that has been very problematic. Perhaps it will change, but I would very much like to see Clojure become a new ClojureScript target.

I recognise your username as the one obsessed with bringing up the existence of native Java/.NET compilers! It seems a losing battle.

Because they do exist, and I think it is important to make people aware Language != Implementation, as young developers seem not to know anything about compiler implementation nowadays.

Maybe my country of origin makes me have a bit of D. Quixote, who knows.

Specifically which one, and how? I've investigated this a lot, and can't find too many people doing this.

Because you want to use a library that was written for Node and not speed time finding (or writing) something similar for the JVM? If you know Node better than the JVM, Clojurescript on Node is very likely more valuable to you when starting out than Clojure on the JVM.

Given JVM and CLR's age, I doubt there is any library for node that doesn't already exist in a similar way for the other platforms.

Just because a library exists for the JVM or CLR doesn't mean a person familiar with Node knows that it exists or the advantages/disadvantages of the 15 libraries that will show up for any given thing they are trying to do. The libraries, profiling tools, performance tuning details. These are the things that make up a platform. Knowing the syntax of Clojure and nothing about the JVM ecosystem isn't going to help you ship any faster. Should a developer in this situation bite the bullet and learn a better supported platform? Maybe. Does everyone have time to do so? Probably not.

Since Clojure was born in the JVM, I doubt anyone learning Clojure will be more at home in node.

not to mention that node-webkit will enable clojurescript to be a major player in large desktop production tools (light-table).

JavaFX, Swing, AWT, SWT, Windows Forms, WPF, XAML,....

Webkit, blah.

webkit might be so so. with node in the formula, and all those npm goodness, I don't think the ones you mention are as nice and as open.