I think the point is "with rules you don't need everything to be and s-expression". I don't know how much to agree or not with that point. Currently I'm of the we'll see where is goes point of view.
> "with rules you don't need everything to be and s-expression"
I am unsure if I would call it a feature.
From a Perl point of view, I think it's the right way to go. There are a few "standard" tricks to simulate extending Perl5, but they often feel hackish. From my understanding this will be more flexible and explicit. I don't have the Lisp experience to compare the two. My guess is Lisp macros will still be more flexible but the gap will be significantly narrowed.
I'm no Lisp guru, not even proficient but isn't saying that kind of missing a large point of Lisp in that code is data and data is a list/sexpresion or what ever it's called?