This conclusion is surprising to me because isn't "Processing" basically some subset of Java? I would have imagined that it would inherit some of the issues with Java as a first language: adding some extra confusion of static typing and a compilation step, plus being relatively verbose. It seems that by choosing Processing you're basically trading the dynamic environment of a Python REPL for ease of starting out with graphical programming. I genuinely don't know which would be more valuable for non-programmers.