I think Fennel and Janet went separate ways fairly early on, and the creator of Fennel focussed primarily on Janet whilst the current maintainer of Fennel is re

I think Fennel and Janet went separate ways fairly early on, and the creator of Fennel focussed primarily on Janet whilst the current maintainer of Fennel is responsible for much (most?) of what you see in Fennel today...So some very different design choices between the two languages, i believe.