I've spent year and a half writing chef as my first "programming" job, like 6 years ago. I learned almost 0 ruby, and that's probably why ruby didn't stick that much.
Yeah, I suspect this might be one reason why Ruby hasn't gained as much traction as others: knowledge doesn't translate well between frameworks, so there's little advantage to re-using the same language for a new project (unless it's a new project in the framework you're already comfortable with).
This is just how Ruby is. It's designed around the idea of building DSLs, so writing in Ruby is almost always an exercise in writing in one DSL or another.