I think there is a minimum threshold to this. I support a large application written in an extremely obscure language (it's basically me and 5 other people on an old yahoo mailing list that make up the entire community). It is terrible. No unit testing frameworks, no http framework for rest calls, no decent UI templating, and on and on. 100% of functionality that I need comes in the form of calls to command line tools.
Obviously, Ruby is way past that threshold, so I do not disagree with what you said at all, but just wanted to point out there is a limit. I would not write a new commercial application in any language today that did not already have strong package system. As one person, you can write a few essential modules that you need, but you cannot write all of them.