What's with this "only Subaru" analogy? What I've found is more along these lines: "Are you sure I'm qualified? I don't feel like I'd be very useful. I've never done Java, only C++ and JS and lisp" "No, you'll be perfect. We don't hire people for specific languages"
I think you're lucky. Of course, my experience is with Python, and trying to get hired by a Ruby shop (no matter my experience outside of work with Ruby or any other language, or my experience with the rest of the stack) is impossible. Perhaps it's a different world the lower down the language abstraction level you look.
Regarding your Ruby-outside-work experience, is it on publicly visible projects?