i don't notice people complaining about needing ruby, python, perl or other things installed for a given tool that depends on them nearly as much as java. interesting.
I actually do (internally) complain when some tool uses python/perl/ruby. It's usually painful to install and maintain compared to most C or Go in this case.
Especially virtualenvs are an axe I like to grind.
python is generally preinstalled on all distributions i know of, because its needed for some utility applications.
ruby on the other hand gets quite a bit of flack as well, because most distributions are so far behind the official ones. that's probably why an embedded ruby binary has become a thing.
Especially virtualenvs are an axe I like to grind.