Many thanks for the detailed answer! I totally agree with most of the points you made. Though, I do think people also opt for Java and other strongly typed languages for other reasons than just ease of integration with legacy systems (stability, speed, better concurrency support, better inheritance support, etc.).
Out of curiosity, how do you see the emergence of languages like Julia? Do you think it has a chance to bridge the worlds of HPC and the development speed of languages like Python and R?