I've found that smaller, more expressive DSL's drastically improve productivity over time. HAML, SaSS, and Compass have saved me an insane amount of time. I'll keep using these types DSL's for as long as they keep making me more productive.

Normally when I think of a ruby DSL, I think of a DSL embedded in a Ruby program (a DSL that is legal ruby syntax). In this case a jabs DSL file is not legal Ruby or javascript, but is turned into valid javascript by a Ruby program.

It is possible that the culture of Ruby does leads to Rubyists writing things like this.