Yup, he's right. Most of these problems have been solved with tools, not by the JDK. If I have arbitrary Java that I want to execute quickly I write a unit test

Yup, he's right. Most of these problems have been solved with tools, not by the JDK. If I have arbitrary Java that I want to execute quickly I write a unit test, not a test program for precisely this reason. I guess it doesn't slow me down, because I know the unit test 'trick', in the same way as I know how to get Light Table to execute arbitrary s-expressions to get around Clojures load times has meant that I'm far less obsessed with Clojures slow startup. Its a problem, sure, but I don't think Java is broken, its just never had the CLI in mind.