Earlier quoted context omitted.
40MB download + requirement of Java Runtime (~100MB) to be present is not quite same. Though to their credit they have packaged all jar dependencies besides JRE in WEB-INF/lib
That's how WAR files get built. It's a very standard mechanism for deploying Java apps. I think having Java on your machine is a reasonable requirement. I mean the equivalent in Ruby would be to have Ruby, install all gems and THEN launch the app.
It's not zero requirements, though. (Go binaries still need platform-specific libc, AFAIK, but it's usually also a reasonable requirement.)