I would never suggest a programmer learn Clojure as their first language, because of the enormous Java stacktraces. Then there's the setup involved (Java, usually Leiningen) to get to "Hello, World" compared to Python or Ruby. Just too many places where the student can get seriously stuck. Clojure's strengths (immutable structures, expression freedom, macros, Java interop, JVM) are not relevant to the new programmer.
Yes, the Java stack traces are probably the worst "ugly" thing in Clojure but from my experience the simplicity of syntax (not to be confused with familiarity, familiar != simple) makes it much easier for someone who's never programmed before to start writing Clojure code vs many other languages where there's a lot of syntax to that you simply need to "know" to get going.
Also, on a more advanced note, I've used https://github.com/ptaoussanis/timbre with great success to get nicely formatted and colored Clojure errors and stack traces.
